314 research outputs found
Far From \u27Easy\u27 Spectroscopy with the 8π and GRIFFIN Spectrometers at TRIUMF-ISAC
The 8π spectrometer, installed at the TRIUMF-ISAC facility, was the world\u27s most sensitive γ-ray spectrometer dedicated to β-decay studies. A description is given of the 8π spectrometer and its auxiliary detectors including the plastic scintillator array SCEPTAR used for β-particle tagging and the Si(Li) array PACES for conversion electron measurements, its moving tape collector, and its data acquisition system. The recent investigation of the decay of 124Cs to study the nuclear structure of 124Xe, and how the β-decay measurements complemented previous Coulomb excitation studies, is highlighted, including the extraction of the deformation parameters for the excited 0+ bands in 124Xe. As a by-product, the decay scheme of the (7+) 124Cs isomeric state, for which the data from the PACES detectors were vital, was studied. Finally, a description of the new GRIFFIN spectrometer, which uses the same auxiliary detectors as the 8π spectrometer, is given
Environmental impacts of cellulose nanowhiskers obtained from tropical vegetal fibers.
Resumo This work compares the environmental impacts of cellulose nanowhiskers obtained from four tropical vegetal fibers: cotton linter, cotton plume, green coconut husk, and sugarcane bagasse. Life cycle impact assessment was performed, according to ISO 14040, considering the following impact categories: eutrophication, human toxicity, ecotoxicity, and climate change. The evaluation showed that the lowest impacts occur when cotton plume is used as the source of cellulose to the extraction of nanowhiskers
Optical and Thermal Design and Analysis of Phase-Change Metalenses for Active Numerical Aperture Control
This is the final version. Available on open access from MDPI via the DOI in this recordThe control of a lens's numerical aperture has potential applications in areas such as photography and imaging, displays, sensing, laser processing and even laser-implosion fusion. In such fields, the ability to control lens properties dynamically is of much interest, and active meta-lenses of various kinds are under investigation due to their modulation speed and compactness. However, as of yet, meta-lenses that explicitly offer dynamic control of a lens's numerical aperture have received little attention. Here, we design and simulate active meta-lenses (specifically, focusing meta-mirrors) using chalcogenide phase-change materials to provide such control. We show that, operating at a wavelength of 3000 nm, our devices can change the numerical aperture by up to a factor of 1.85 and operate at optical intensities of the order of 1.2 × 109 Wm-2. Furthermore, we show the scalability of our design towards shorter wavelengths (visible spectrum), where we demonstrate a change in NA by a factor of 1.92.Engineering and Physical Sciences Research Council (EPSRC)Margarita Salas fellowshi
Lens numerical aperture control with phase-change metasurfaces
This is the author accepted manuscript.The control of lens numerical aperture has many applications, including photography, imaging, and laser processing. Here we introduce active control of numerical aperture via a focusing phase-change meta-mirror. This can potentially operate at high speed in a low cost, light and compact format. We demonstrate designs for both infrared (3000 nm) and visible (632.8 nm) wavelengths.Engineering and Physical Sciences Research Council (EPSRC)Atomic Weapons Establishment (AWE
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The energy-related inventions program: Continuing benefits to the inventor community
This report provides information on the economic, energy, and environmental impacts of inventions supported by the Energy-Related Inventions Program (ERIP) - a technology commercialization program jointly operated by the U.S. Department of Energy (DOE) and the National Institute of Standards and Technology (NIST). It describes the results of the latest in a series of ERIP evaluation projects that have been completed since 1980. The period of interest is 1980 through 1994. The evaluation is based on data collected in 1995 through mail and telephone surveys of 211 program participants, and historical data collected during previous evaluations for an additional 253 participants. As of September 1993, a total of 609 inventions had been recommended to DOE by NIST, which screens all submitted inventions for technical merit, potential for commercial success, and potential energy impact. By the end of 1994, at least 144 (or 24%) of these inventions had entered the market, generating total cumulative sales of 2.3 million, and over the lifetime of the program, royalties total 47.5 million in grants awarded from 1975 through 1994 and 3.4 million in individual income taxes to the U.S. Treasury. Finally, approximately $334 million of energy expenditures were saved in 1994 as a result of the commercial success of five ERIP projects. These energy savings resulted in reduced emissions of 2.1 million metric tons of carbon in 1994 alone
Switching of Phase-Change Optical Metasurfaces via Remote Thermal Sources
This is the final version.Atomic Weapons Establishment (AWE) plcEngineering and Physical Sciences Research Council (EPSRC
Remote Thermal Sources for Switching Phase-Change Material-Based Metasurfaces
This is the final version.Atomic Weapons Establishment (AWE) plcEngineering and Physical Sciences Research Council (EPSRC
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