2,677 research outputs found
Microgrids for Improving Manufacturing Energy Efficiency
Thirty-one percent of annual energy consumption in the United States occurs within the industrial sector, where manufacturing processes account for the largest amount of energy consumption and carbon emissions. For this reason, energy efficiency in manufacturing facilities is increasingly important for reducing operating costs and improving profits. Using microgrids to generate local sustainable power should reduce energy consumption from the main utility grid along with energy costs and carbon emissions. Also, microgrids have the potential to serve as reliable energy generators in international locations where the utility grid is often unstable. For this research, a smart microgrid system was designed as part of an innovative load management option to improve energy utilization through active Demand-Side Management (DSM). An intelligent active DSM algorithm was developed to manage the intermittent nature of the microgrid and instantaneous demand of the site loads. The controlling algorithm required two input signals; one from the microgrid indicating the availability of renewable energy and another from the manufacturing process indicating energy use as a percent of peak production. Based on these inputs the algorithm had three modes of operation: normal (business as usual), curtailment (shutting off non-critical loads), and energy storage. The results show that active management of a manufacturing microgrid has the potential for saving energy and money by intelligent scheduling of process loads
A Novel Microgrid Demand-Side Management System for Manufacturing Facilities
Thirty-one percent of annual energy consumption in the United States occurs within the industrial sector, where manufacturing processes account for the largest amount of energy consumption and carbon emissions. For this reason, energy efficiency in manufacturing facilities is increasingly important for reducing operating costs and improving profits. Using microgrids to generate local sustainable power should reduce energy consumption from the main utility grid along with energy costs and carbon emissions. Also, microgrids have the potential to serve as reliable energy generators in international locations where the utility grid is often unstable.
For this research, a manufacturing process that had approximately 20 kW of peak demand was matched with a solar photovoltaic array that had a peak output of approximately 3 KW. An innovative Demand-Side Management (DSM) strategy was developed to manage the process loads as part of this smart microgrid system. The DSM algorithm managed the intermittent nature of the microgrid and the instantaneous demand of the manufacturing process. The control algorithm required three input signals; one from the microgrid indicating the availability of renewable energy, another from the manufacturing process indicating energy use as a percent of peak production, and historical data for renewable sources and facility demand. Based on these inputs the algorithm had three modes of operation: normal (business as usual), curtailment (shutting off non-critical loads), and energy storage.
The results show that a real-time management of a manufacturing process with a microgrid will reduce electrical consumption and peak demand. The renewable energy system for this research was rated to provide up to 13% of the total manufacturing capacity. With actively managing the process loads with the DSM program alone, electrical consumption from the utility grid was reduced by 17% on average. An additional 24% reduction was accomplished when the microgrid and DSM program was enabled together, resulting in a total reduction of 37%. On average, peak demand was reduced by 6%, but due to the intermittency of the renewable source and the billing structure for peak demand, only a 1% reduction was obtained. During a billing period, it only takes one day when solar irradiance is poor to affect the demand reduction capabilities. To achieve further demand reduction, energy storage should be introduced and integrated
Multiabsorber Transition-Edge Sensors for X-Ray Astronomy
We are developing arrays of position-sensitive microcalorimeters for future x-ray astronomy applications. These position-sensitive devices commonly referred to as hydras consist of multiple x-ray absorbers, each with a different thermal coupling to a single-transition-edge sensor microcalorimeter. Their development is motivated by a desire to achieve very large pixel arrays with some modest compromise in performance. We report on the design, optimization, and first results from devices with small pitch pixels (<75 m) being developed for a high-angular and energy resolution imaging spectrometer for Lynx. The Lynx x-ray space telescope is a flagship mission concept under study for the National Academy of Science 2020 decadal survey. Broadband full-width-half-maximum (FWHM) resolution measurements on a 9-pixel hydra have demonstrated E(FWHM) = 2.23 0.14 eV at Al-K, E(FWHM) = 2.44 0.29 eV at Mn-K, and E(FWHM) = 3.39 0.23 eV at Cu-K. Position discrimination is demonstrated to energies below <1 keV and the device performance is well-described by a finite-element model. Results from a prototype 20-pixel hydra with absorbers on a 50-m pitch have shown E(FWHM) = 3.38 0.20 eV at Cr-K1. We are now optimizing designs specifically for Lynx and extending the number of absorbers up to 25/hydra. Numerical simulation suggests optimized designs could achieve 3 eV while being compatible with the bandwidth requirements of the state-of-the art multiplexed readout schemes, thus making a 100,000 pixel microcalorimeter instrument a realistic goal
Outpatient Opioid Prescriptions are Associated with Future Substance use Disorders and Overdose Following Adolescent Trauma
Objective:
This study aims to determine if outpatient opioid prescriptions are associated with future substance use disorder (SUD) diagnoses and overdose in injured adolescents five years following hospital discharge.
Summary Background Data:
Approximately, 1 in 8 adolescents are diagnosed with an SUD and 1 in 10 experience an overdose in the five years following injury. State laws have become more restrictive on opioid prescribing by acute care providers for treating pain, however, prescriptions from other outpatient providers are still often obtained.
Methods:
This was a retrospective cohort study of patients ages 12–18 admitted to two level I trauma centers. Demographic and clinical data contained in trauma registries were linked to a regional database containing five years of electronic health records and prescription data. Regression models assessed whether number of outpatient opioid prescription fills after discharge at different time points in recovery were associated with a new SUD diagnosis or overdose, while controlling for demographic and injury characteristics, as well as depression and PTSD diagnoses.
Results:
We linked 669 patients (90.9%) from trauma registries to a regional health information exchange database. Each prescription opioid refill in the first 3 months after discharge increased the likelihood of new SUD diagnoses by 55% (OR:1.55, CI:1.04–2.32). Odds of overdose increased with ongoing opioid use over 2–4 years post-discharge (p = 0.016–0.025).
Conclusions:
Short-term outpatient opioid prescribing over the first few months of recovery had the largest effect on developing an SUD, while long-term prescription use over multiple years was associated with a future overdose
Leading twist nuclear shadowing phenomena in hard processes with nuclei
We present and discuss the theory and phenomenology of the leading twist
theory of nuclear shadowing which is based on the combination of the
generalization of the Gribov-Glauber theory, QCD factorization theorems, and
the HERA QCD analysis of diffraction in lepton-proton deep inelastic scattering
(DIS). We apply this technique for the analysis of a wide range of hard
processes with nuclei---inclusive DIS on deuterons, medium-range and heavy
nuclei, coherent and incoherent diffractive DIS with nuclei, and hard
diffraction in proton-nucleus scattering---and make predictions for the effect
of nuclear shadowing in the corresponding sea quark and gluon parton
distributions. We also analyze the role of the leading twist nuclear shadowing
in generalized parton distributions in nuclei and in certain characteristics of
final states in nuclear DIS. We discuss the limits of applicability of the
leading twist approximation for small x scattering off nuclei and the onset of
the black disk regime and methods of detecting it. It will be possible to check
many of our predictions in the near future in the studies of the
ultraperipheral collisions at the Large Hadron Collider (LHC). Further checks
will be possible in pA collisions at the LHC and forward hadron production at
the Relativistic Heavy Ion Collider (RHIC). Detailed tests will be possible at
an Electron-Ion Collider (EIC) in the USA and at the Large Hadron-Electron
Collider (LHeC) at CERN.Comment: 253 pages, 103 figures, 7 tables. The final published versio
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Open Science principles for accelerating trait-based science across the Tree of Life.
Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles-open data, open source and open methods-is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance widespread adoption of these principles, we introduce the Open Traits Network (OTN), a global, decentralized community welcoming all researchers and institutions pursuing the collaborative goal of standardizing and integrating trait data across organisms. We demonstrate how adherence to Open Science principles is key to the OTN community and outline five activities that can accelerate the synthesis of trait data across the Tree of Life, thereby facilitating rapid advances to address scientific inquiries and environmental issues. Lessons learned along the path to a global synthesis of trait data will provide a framework for addressing similarly complex data science and informatics challenges
Performance of an X-Ray Microcalorimeter with a 240 Micron Absorber and a 50 Micron TES Bilayer
We have been developing superconducting transition-edge sensor (TES) microcalorimeters for a variety of potential astrophysics missions, including Athena. The X-ray Integral Field Unit (X-IFU) instrument on this mission requires close-packed pixels on a 0.25 mm pitch, and high quantum efficiency between 0.2 and 12 keV. The traditional approach within our group has been to use square TES bilayers on molybdenum and gold that are between 100 and 140 microns in size, deposited on silicon nitride membranes to provide a weak thermal conductance to a 50 mK heat bath temperature. It has been shown that normal metal stripes on top of the bilayer are needed to keep the unexplained noise at a level consistent with the expected based upon estimates for the non-equilibrium non-linear Johnson noise.In this work we describe a new approach in which we use a square TES bilayer that is 50 microns in size. While the weak link effect is much stronger in this size of TES, we have found that excellent spectral performance can be achieved without the need for any normal metal strips on top of the TES. A spectral performance of 1.58 eV at 6 KeV has been achieved, the best resolution seen in any of our devices with this pixel size. The absence of normal metal stripes has led to more uniform transition shapes, and more reliable excellent spectral performance. The smaller TES size has meant that that the thermal conductance to the heat bath, determined by the perimeter length of the TES and the membrane thickness, is lower than on previous devices, and thus has a lower count rate capability. This is an advantage for low count-rate applications where the slower speed enables easier multiplexing in the read-out, thus potential higher multiplexing factors. In order to recover the higher count rate capabilities, a potential path exits using thicker silicon nitride membranes to increase the thermal conductance to the heat bath
Design of Magnetic Shielding and Field Coils for a TES X-Ray Microcalorimeter Test Platform
The performance of Transition-Edge Sensors (TES) and their SQUID multiplexed read-outs are very sensitive to the ambient magnetic field from Earth and fluctuations that can arise due to fluctuating magnetic fields outside of the focal plane assembly from the Adiabatic Demagnetization Refrigerator (ADR).Thus, the experimental platform we are building to test the FPA of the X-ray Integral Field Unit (X-IFU) of the Athena mission needs to include a series of shields and a coil in order to meet the following requirement of magnetic field density and uniformity
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