213 research outputs found
Ponderomotive entangling of atomic motions
We propose the use of ponderomotive forces to entangle the motions of
different atoms. Two situations are analyzed: one where the atoms belong to the
same optical cavity and interact with the same radiation field mode; the other
where each atom is placed in own optical cavity and the output field of one
cavity enters the other.Comment: Revtex file, five pages, two eps figure
Ultrathin 2 nm gold as ideal impedance-matched absorber for infrared light
Thermal detectors are a cornerstone of infrared (IR) and terahertz (THz)
technology due to their broad spectral range. These detectors call for suitable
broad spectral absorbers with minimalthermal mass. Often this is realized by
plasmonic absorbers, which ensure a high absorptivity butonly for a narrow
spectral band. Alternativly, a common approach is based on impedance-matching
the sheet resistance of a thin metallic film to half the free-space impedance.
Thereby, it is possible to achieve a wavelength-independent absorptivity of up
to 50 %, depending on the dielectric properties of the underlying substrate.
However, existing absorber films typicallyrequire a thickness of the order of
tens of nanometers, such as titanium nitride (14 nm), whichcan significantly
deteriorate the response of a thermal transducers. Here, we present the
application of ultrathin gold (2 nm) on top of a 1.2 nm copper oxide seed layer
as an effective IR absorber. An almost wavelength-independent and long-time
stable absorptivity of 47(3) %, ranging from 2 m to 20 m, could be
obtained and is further discussed. The presented gold thin-film represents
analmost ideal impedance-matched IR absorber that allows a significant
improvement of state-of-the-art thermal detector technology
La riboflavina (vitamina B2) reduce el deterioro de pimientos mínimamente procesados
La riboflavina (vitamina B2) generalmente se reconoce como un aditivo seguro (GRAS). Se utiliza en alimentos para fortificar ciertos productos con bajo contenido natural o compensar las posibles pérdidas de vitaminas durante la elaboración. En este trabajo, se estudió el efecto de tratamientos por inmersión en riboflavina, previos al almacenamiento, en el mantenimiento de la calidad de pimiento verde recién cortado (Capsicum annum L). Inicialmente se ensayó la eficacia de diferentes concentraciones de riboflavina (0, control; 1; 10 y 100 μmol L-1) para reducir el deterioro en los bastones de pimiento cortado (5 × 1 cm) almacenados en una condición de abuso térmico, 8 ºC. El tratamiento de imersión por 5 min en 100 μmol L−1 de riboflavina controló eficazmente el deterioro de los pimientos y, por lo tanto, fue seleccionado para una evaluación adicional en pimientos almacenados a 4 ºC por 0, 6, 9 y 12 d.Laboratorio de Investigación en Productos AgroindustrialesConsejo Nacional de Investigaciones Científicas y TécnicasInstituto Nacional de Tecnología Agropecuari
Alzheimer's Disease: a Review of its Visual System Neuropathology. Optical Coherence Tomography-a Potential Role As a Study Tool in Vivo
Alzheimer's disease (AD) is a prevalent, long-term progressive degenerative disorder with great social impact. It is currently thought that, in addition to neurodegeneration, vascular changes also play a role in the pathophysiology of the disease. Visual symptoms are frequent and are an early clinical manifestation; a number of psychophysiologic changes occur in visual function, including visual field defects, abnormal contrast sensitivity, abnormalities in color vision, depth perception deficits, and motion detection abnormalities. These visual changes were initially believed to be solely due to neurodegeneration in the posterior visual pathway. However, evidence from pathology studies in both animal models of AD and humans has demonstrated that neurodegeneration also takes place in the anterior visual pathway, with involvement of the retinal ganglion cells' (RGCs) dendrites, somata, and axons in the optic nerve. These studies additionally showed that patients with AD have changes in retinal and choroidal microvasculature. Pathology findings have been corroborated in in-vivo assessment of the retina and optic nerve head (ONH), as well as the retinal and choroidal vasculature. Optical coherence tomography (OCT) in particular has shown great utility in the assessment of these changes, and it may become a useful tool for early detection and monitoring disease progression in AD. The authors make a review of the current understanding of retinal and choroidal pathological changes in patients with AD, with particular focus on in-vivo evidence of retinal and choroidal neurodegenerative and microvascular changes using OCT technology.info:eu-repo/semantics/publishedVersio
Optical Larmor Beat Detection of High-Resolution Nuclear Magnetic Resonance in a Semiconductor Heterostructure
Novel High Molecular Weight Aromatic Fluorinated Polymers from One-Pot, Metal-Free Step Polymerizations
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