2,581 research outputs found
High optical quality cellulose thin films grown from raw natural cotton by pulsed laser deposition
No full textRaw natural cotton harvested in the fields of Thessaly, Central Greece, was used to grow high optical quality, highly durable cellulose thin films by pulsed laser deposition, using 193 nm ArF laser pulses. Standard pulsed laser deposition conditions at room temperature were applied and raw, unprocessed, natural cotton targets were used. The semi-crystalline cellulose of natural cotton converts to very durable solid films that are fully transparent in the visible wavelength range and exhibit amorphous structure. Thin film quality and surface morphology are parametrically investigated and show a strong dependence on laser fluence. Films deposited at the lowest fluence levels ~ 5 mJ/cm2 on target, close to the observed ablation threshold, exhibit roughness of ~ 1.7 nm rms. The high optical quality of the grown biocompatible cellulose materials proves the unique capacities of laser deposition and processing methods and promise novel biophotonics and other interdisciplinary applications for the health and safety of the citizen
Closing the loop: The role of audit in reducing groin complications associated with coronary angiography
No full textMcCleary, Alistair J. ; Raptis, Sper
Redox-Active Metal Oxides
No full textDr. Raptis obtained his Ph.D in Inorganic Chemistry from Texas A & M University. His research is focused on the synthesis of novel metal complexes with unusual topologies, electron transfer and magnetic properties. The synthesis and study of a new class of iron-based MRI contrast agents has been a major theme of his recent work. The study of porous metal-organic frameworks (MOFs) for the selective sorption of gases is a new direction currently pursued by Dr. Raptis’ laboratory. Susana Herrera (Logesh Mathivathanan, Raphael G, Raptis) “Bio-inspired Dinuclear Copper Oxygenation Catalysts: Synthesis, Characterization, and Reactivity Studies” Zimarayn Urdaneta (D.I. Kreiger, Raphael G. Raptis) “Studies Toward Copper Pyrazolate Based Water Oxidation” Raphael G. Raptis (Raphael G. Raptis) “Redox-Active Metal Oxides
A Remark on Configuration Spaces of Two Points
No full textWe prove a homotopy invariance result for a certain covering space of the space of ordered configurations of two points in M x X where M is a closed smooth manifold and X is any fixed aspherical space which is not a point
Soil moisture as a potential variable for tracking and quantifying irrigation: A case study with proximal gamma-ray spectroscopy data
No full textThe global warming effects put in danger global water availability and make necessary to decrease water wastage, e.g., by monitoring global irrigation. Despite this, global irrigation information is scarce due to the absence of a solid estimation technique. In this study, we applied an innovative approach to retrieve irrigation water from high spatial and temporal resolution Soil Moisture (SM) data obtained from an advanced sensor based on Proximal Gamma-Ray (PGR) spectroscopy, in a field located in Emilia Romagna (Italy). The results show that SM is a key variable to obtain information about the amount of water applied to plants, with Pearson correlation between observed and estimated daily irrigation data ranges from 0.88 to 0.91 by using different calibration methodology. With the aim of reproducing the working conditions of satellites measuring soil moisture, we sub-sampled SM hourly time series at larger time steps. The results demonstrated that the methodology is still capable to perform the daily (weekly) irrigation estimation with Pearson Correlation around 0.6 (0.7) if the time step is not greater than 36 (48) hours
Sur l’autogestion algérienne et le Tiers monde. Entretiens avec A. Ben Bella
No full textBen Bella Ahmed, Raptis Michel. Sur l’autogestion algérienne et le Tiers monde. Entretiens avec A. Ben Bella. In: Autogestions, NS N°7, 1981. Irlande : au-delà du terrorisme. pp. 337-345
Polymer coated microfabricated interdigitated electrodes arrays for gas sensing applications
No full textInterDigitated Capacitive (IDC) sensor arrays are fabricated with conventional microelectronics-micromachining technologies on quartz substrates. After fabrication, a polymeric well is patterned around each IDC to precisely define the sensing area and thus deposit coatings of various polymers, by drop casting, in a reproducible and controlled manner. The gas sensing performance of the IDC array is presented for humidity and p-xylene.</jats:p
GreenCrowd: Toward a Holistic Algorithmic Crowd Charging Framework
No full textCrowd charging represents an alternative peer-to-peer energy replenishment option for mobile users to align with the circular economy paradigm. Following this option, users bound by finite resource capacity utilize the energy from external to the crowd wireless or wired energy sources (such as shared chargers), and internal to the crowd energy sources (such as mobile devices, via wireless power transfer). If designed carefully, such utilization can boost the energy availability of users and provide energy ubiquitously to their devices for making them functional for longer. This article proposes the GreenCrowd framework, introducing a privacy-by-design in the digital domain crowd charging process, the architecture of which incorporates multiple crowd-* components, such as online social information exploitation, algorithmic battery aging mitigation, user reward mechanisms, and advanced decision making. The primary aim of article is to present the technological and applicative requirements and constraints of GreenCrowd, and provide practical evidence on its feasibility
Finitary Čech-de Rham cohomology
No full textThe present paper continues (Mallios &amp; Rapfis, International Journal of Theoretical Physics, 2001, 40, 1885) and studies the curved finitary spacetime sheaves of incidence algebras presented therein from a Čech cohomological perspective. In particular, we entertain the possibility of constructing a nontrivial de Rham complex on these finite dimensional algebra sheaves along the lines of the first author's axiomatic approach to differential geometry via the theory of vector and algebra sheaves (Mallios, Geometry of Vector Sheaves. An Axiomtic Approach to Differential Geometry, Vols. 1-2, Kluwer, Dordrecht, 1998a; Mathematica Japonica (International Plaza), 1998b, 48, 93). The upshot of this study is that important "classical" differential geometric constructions and results usually thought of as being intimately associated with C∞-smooth manifolds carry through, virtually unaltered, to the finitary-algebraic regime with the help of some quite universal, because abstract, ideas taken mainly from sheaf-cohomology as developed in Mallios (1998a,b). At the end of the paper, and due to the fact that the incidence algebras involved have been interpreted as quantum causal sets (Raptis, International Journal of Theoretical Physics, 2000, 39, 1233; Mallios &amp; Rapfis, 2001), we discuss how these ideas may be used in certain aspects of current research on discrete Lorentzian quantum gravity
Finitary topos for locally finite, causal and quantal vacuum einstein gravity
No full textThe pentalogy (Mallios, A. and Raptis, I. (2001). International Journal of Theoretical Physics 40, 1885; Mallios, A. and Raptis, I. (2002). International Journal of Theoretical Physics 41, 1857; Mallios, A. and Raptis, I. (2003).International Journal of Theoretical Physics 42, 1479; Mallios, A. and Raptis, I. (2004). 'paper-book'/research monograph); I. Raptis (2005). International Journal of Theoretical Physics (to appear)is brought to its categorical climax by organizing the curved finitary spacetime sheaves of quantumcausal sets involved therein, on which a finitary (:locally finite), singularity-free, background manifold independent and geometrically prequantized version of the gravitational vacuum Einstein field equations were seen to hold, into a topos structure [InlineMediaObject not available: see fulltext.]. We show that the category of finitary differential triads [InlineMediaObject not available: see fulltext.] is a finitary instance of an elementary topos proper in the original sense dueto Lawvere and Tierney. We present in the light of Abstract Differential Geometry (ADG) a Grothendieck-type of generalization of Sorkin's finitary substitutes of continuous spacetime manifoldtopologies, the latter's topological refinement inverse systems of locally finite coverings and their associated coarse graining sieves, the upshot being that [InlineMediaObject not available: see fulltext.] is also a finitary example of a Grothendieck topos. In the process, we discover that the subobject classifier Ω fcq of [InlineMediaObject not available: see fulltext.] is a Heyting algebra type of object, thus we infer that the internal logic of our finitary topos is intuitionistic, as expected. We also introduce the new notion of 'finitary differential geometric morphism' which, as befits ADG, gives a differential geometric slant to Sorkin's purely topological acts of refinement (:coarse graining). Based on finitary differential geometric morphisms regarded as natural transformations of the relevant sheaf categories, we observe that the functorial ADG-theoretic version of the principle of general covariance of GeneralRelativity is preserved under topological refinement. The paper closes with a thorough discussion of four future routes we could take in order to further develop our topos-theoretic perspective on ADG-gravity along certain categorical trends in current quantum gravity research. © Springer Science+Business Media, LLC 2007
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