Search results for " Reflection"

Carbon coatings for soft-x-ray reflectivity enhancement

2007

In X-ray astronomical telescopes, the focalization of the radiation is achieved by means of grazing incidence Wolter I (parabola + hyperbola) optics in total reflection regime. In general, high density materials (e.g. Au, Pt, Ir, W) are used as reflecting coatings, in order to increase as much as possible the cut-off angles and energies for total reflection. However these materials present an important reduction of the reflectivity between 0.2 and 5 keV, due to the photoabsorption, and this phenomenon is particularly enhanced in correspondence of the M absorption edges (between 2 and 3.5 keV). In general, this determines a strong decrease of the telescope effective area. To overcome the pro…

The Calatrava model: reflections on resilience and urban plasticity

2016

ABSTRACTThe article introduces a critical reflection on the effects that the version of cultural capitalism based on large events and architectural symbols has on the resilience of cities when used as an engine, and not as a complement to the policies of urban transformation. The article introduces as a case of study the so-called ‘Calatrava model’ of the city of Valencia. The model of a cultural bubble of Valencia, designed to enable a new space, is developed and contrasted with other two examples of urban transformation designed to revitalize spaces: Bilbao – symbolically represented by Frank Gehry's Guggenheim museum – and the Barcelona 22@ – symbolically represented by Jean Nouvel's Agb…

Kerr and Faraday Rotations of Magneto-Optical Multilayers under the Condition of Total Internal Reflection

1999

Four-Color Infrared Bolometer System for One-Meter Telescope

1978

As a part of the collaborative program between the University of Palermo and the Center for Astrophysics (HCO/SAO) a far infrared photometer has been designed, fabricated and tested by the Univsity of Palermo to be used as a focal plane instrument on the Center of Astrophysics/University of Arizona balloon-borne 102 cm telescope (Fazio et a1. 1974).

Determinant role of the edges in defining surface plasmon propagation in stripe waveguides and tapered concentrators

2012

International audience; In this paper, we experimentally show the effect of waveguide discontinuity on the propagation of the surface plasmon in metal stripes and tapered terminations. Dual-plane leakage microscopy and near-field microscopy were performed on Au stripes with varied widths to imag29e the surface plasmon intensity distribution in real and reciprocal spaces. We unambiguously demonstrate that edge diffraction is the limiting process determining the cutoff conditions of the surface plasmon mode. Finally, we determine the optimal tapered geometry leading to the highest transmission.

Preparation of organic monolithic columns in polytetrafluoroethylene tubes for reversed-phase liquid chromatography

2017

[EN] In this work, a method for the preparation and anchoring of polymeric monoliths in a polytetrafluoroethylene (PTFE) tubing as a column housing for microbore HPLC is described. In order to assure a covalent attachment of the monolith to the inner wall of the PTFE tube, a two-step procedure was developed. Two surface etching reagents, a commercial sodium naphthalene solution (Fluoroetch®), or mixtures of H2O2 and H2SO4, were tried and compared. Then, the obtained hydroxyl groups on the PTFE surface were modified by methacryloylation. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM) confirmed the successful modification…

Correlating Schiff Moments in the Light Actinides with Octupole Moments

2018

We show that the measured intrinsic octupole moments of $^{220}$Rn, $^{224}$Ra, and $^{226}$Ra constrain the intrinsic Schiff moments of $^{225}$Ra$^{221}$Rn, $^{223}$Rn, $^{223}$Fr, $^{225}$Ra, and $^{229}$Pa. The result is a dramatically reduced uncertainty in intrinsic Schiff moments. Direct measurements of octupole moments in odd nuclei will reduce the uncertainty even more. The only significant source of nuclear-physics error in the laboratory Schiff moments will then be the intrinsic matrix elements of the time-reversal non-invariant interaction produced by CP-violating fundamental physics. Those matrix elements are also correlated with octupole moments, but with a larger systematic u…

The [Fe(etz)6](BF4)2 Spin-Crossover System—Part One: High-Spin ⇌ Low-Spin Transition in Two Lattice Sites

1996

The [Fe(etz),](BF,), spin-cross-over system (etz = 1-ethyl-1 H-tetrazole) crystallizes in space group P1, with the following lattice constants at 298 K: a 10.419(3), b=15.709(1), c = 18.890(2) A = = 71.223(9), =77.986(10), and = 84.62(1)° V = 2862.0(9) A3 and Z = 3. Two nonequivalent lattice sites, one without (site A) and one with (site B) inversion symmetry, are observed. The population of the two sites nA:nB is 2:l. Iron(II) on site A undergoes a thermal low-spin (LS) high-spin (HS) transition with T1/2I, = 105 K. whereas that on site B remains in the high-spin state down to cryogenic temperatures. Application of external pressure of up to 1200 bar between 200 and 60 K does not cause for…

Emission of Rhodamine B in PMMA opals for luminescent solar concentrators

2012

In conventional luminescent solar concentrators (LSC) incident light is absorbed by luminophores and emitted isotropically. Most of the emitted light is trapped inside the LSC by total internal reflection and guided to solar cells at the edges. Light emitted towards the surfaces, however, is lost in the escape cone. Furthermore, when the luminophore emits light in its absorption range, light is lost due to reabsorption. To overcome these losses, we embed the luminescent material in photonic structures to influence the emission characteristics. Directional and spectral redistribution of emission is supposed to enhance the light guiding in LSCs and reduce reabsorption losses. For this purpose…

Protein Adsorption Hysteresis and Transient States of Fibrinogen and BMP-2 as Model Mechanisms for Proteome-Binding to Implants

2020

Abstract Protein adsorption studies returned to the focus of medical therapeutics, when it was found that up to 2500 non-plasma proteins adsorbed to hip implants during arthroplastic surgery, challenging peri-implant healing models. Questions have re-emerged as to the implications of uncontrolled protein unfolding after adsorption. In past studies on the cooperativity of protein binding we discovered protein adsorption hysteresis, a thermodynamically irreversible process. The present precursory study comprises real-time kinetic (TIRF-Rheometry) and equilibrium (125I-tracer ) studies on the hysteretic binding of fibrinogen and rhBMP-2 to titanium and glass surfaces via transient states. Ther…