Department of Energy--Office of Energy Efficiency and Renewable Energy Geothermal Program: Geothermal Risk Mitigation Strategies Report

2008 ◽  
Author(s):  
None None
2006 ◽  
Vol 2 (S236) ◽  
pp. 353-362 ◽  
Author(s):  
Željko Ivezić ◽  
J. Anthony Tyson ◽  
Mario Jurić ◽  
Jeremy Kubica ◽  
Andrew Connolly ◽  
...  

AbstractThe Large Synoptic Survey Telescope (LSST) is currently by far the most ambitious proposed ground-based optical survey. With initial funding from the National Science Foundation (NSF), Department of Energy (DOE) laboratories, and private sponsors, the design and development efforts are well underway at many institutions, including top universities and national laboratories. Solar System mapping is one of the four key scientific design drivers, with emphasis on efficient Near-Earth Object (NEO) and Potentially Hazardous Asteroid (PHA) detection, orbit determination, and characterization. The LSST system will be sited at Cerro Pachon in northern Chile. In a continuous observing campaign of pairs of 15 s exposures of its 3,200 megapixel camera, LSST will cover the entire available sky every three nights in two photometric bands to a depth of V=25 per visit (two exposures), with exquisitely accurate astrometry and photometry. Over the proposed survey lifetime of 10 years, each sky location would be visited about 1000 times, with the total exposure time of 8 hours distributed over several broad photometric bandpasses. The baseline design satisfies strong constraints on the cadence of observations mandated by PHAs such as closely spaced pairs of observations to link different detections and short exposures to avoid trailing losses. Due to frequent repeat visits LSST will effectively provide its own follow-up to derive orbits for detected moving objects.Detailed modeling of LSST operations, incorporating real historical weather and seeing data from Cerro Pachon, shows that LSST using its baseline design cadence could find 90% of the PHAs with diameters larger than 250 m, and 75% of those greater than 140 m within ten years. However, by optimizing sky coverage, the ongoing simulations suggest that the LSST system, with its first light in 2013, can reach the Congressional mandate of cataloging 90% of PHAs larger than 140m by 2020. In addition to detecting, tracking, and determining orbits for these PHAs, LSST will also provide valuable data on their physical and chemical characteristics (accurate color and variability measurements), constraining PHA properties relevant for risk mitigation strategies. In order to fulfill the Congressional mandate, a survey with an etendue of at least several hundred m2deg2, and a sophisticated and robust data processing system is required. It is fortunate that the same hardware, software and cadence requirements are driven by science unrelated to NEOs: LSST reaches the threshold where different science drivers and different agencies (NSF, DOE and NASA) can work together to efficiently achieve seemingly disjoint, but deeply connected, goals.


Author(s):  
Agnes Ann Feemster ◽  
Melissa Augustino ◽  
Rosemary Duncan ◽  
Anand Khandoobhai ◽  
Meghan Rowcliffe

Abstract Disclaimer In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. Purpose The purpose of this study was to identify potential failure points in a new chemotherapy preparation technology and to implement changes that prevent or minimize the consequences of those failures before they occur using the failure modes and effects analysis (FMEA) approach. Methods An FMEA was conducted by a team of medication safety pharmacists, oncology pharmacists and technicians, leadership from informatics, investigational drug, and medication safety services, and representatives from the technology vendor. Failure modes were scored using both Risk Priority Number (RPN) and Risk Hazard Index (RHI) scores. Results The chemotherapy preparation workflow was defined in a 41-step process with 16 failure modes. The RPN and RHI scores were identical for each failure mode because all failure modes were considered detectable. Five failure modes, all attributable to user error, were deemed to pose the highest risk. Mitigation strategies and system changes were identified for 2 failure modes, with subsequent system modifications resulting in reduced risk. Conclusion The FMEA was a useful tool for risk mitigation and workflow optimization prior to implementation of an intravenous compounding technology. The process of conducting this study served as a collaborative and proactive approach to reducing the potential for medication errors upon adoption of new technology into the chemotherapy preparation process.


Author(s):  
Paolo Pezzini ◽  
David Tucker ◽  
Alberto Traverso

A new emergency shutdown procedure for a direct-fired fuel cell turbine hybrid power system was evaluated using a hardware-based simulation of an integrated gasifier/fuel cell/turbine hybrid cycle (IGFC), implemented through the Hybrid Performance (Hyper) project at the National Energy Technology Laboratory, U.S. Department of Energy (NETL). The Hyper facility is designed to explore dynamic operation of hybrid systems and quantitatively characterize such transient behavior. It is possible to model, test, and evaluate the effects of different parameters on the design and operation of a gasifier/fuel cell/gas turbine hybrid system and provide a means of quantifying risk mitigation strategies. An open-loop system analysis regarding the dynamic effect of bleed air, cold air bypass, and load bank is presented in order to evaluate the combination of these three main actuators during emergency shutdown. In the previous Hybrid control system architecture, catastrophic compressor failures were observed when the fuel and load bank were cut off during emergency shutdown strategy. Improvements were achieved using a nonlinear fuel valve ramp down when the load bank was not operating. Experiments in load bank operation show compressor surge and stall after emergency shutdown activation. The difficulties in finding an optimal compressor and cathode mass flow for mitigation of surge and stall using these actuators are illustrated.


Author(s):  
Leigh McCue

Abstract The purpose of this work is to develop a computationally efficient model of viral spread that can be utilized to better understand influences of stochastic factors on a large-scale system - such as the air traffic network. A particle-based model of passengers and seats aboard a single-cabin 737-800 is developed for use as a demonstration of concept on tracking the propagation of a virus through the aircraft's passenger compartment over multiple flights. The model is sufficiently computationally efficient so as to be viable for Monte Carlo simulation to capture various stochastic effects, such as number of passengers, number of initially sick passengers, seating locations of passengers, and baseline health of each passenger. The computational tool is then exercised in demonstration for assessing risk mitigation of intervention strategies, such as passenger-driven cleaning of seating environments and elimination of middle seating.


2020 ◽  
Vol 4;23 (7;4) ◽  
pp. E335-E342
Author(s):  
Jason Friedrich

Background: More patients with cardiac implantable electrical devices (CIEDs) are presenting to spine and pain practices for radiofrequency ablation (RFA) procedures for chronic pain. Although the potential for electromagnetic interference (EMI) affecting CIED function is known with RFA procedures, available guidelines do not specifically address CIED management for percutaneous RFA for zygapophyseal (z-joint) joint pain, and thus physician practice may vary. Objectives: To better understand current practices of physicians who perform RFA for chronic z-joint pain with respect to management of CIEDs. Perioperative CIED management guidelines are also reviewed to specifically address risk mitigation strategies for potential EMI created by ambulatory percutaneous spine RFA procedures. Study Design: Web-based provider survey and narrative review. Setting: Multispecialty pain clinic, academic medical center. Methods: A web-based survey was created using Research Electronic Data Capture (REDCap). A survey link was provided via e-mail to active members of the Spine Intervention Society (SIS), American Society of Regional Anesthesia and Pain Medicine, as well as distributed freely to community Pain Physicians and any receptive academic departments of PM&R or Anesthesiology. The narrative review summarizes pertinent case series, review articles, a SIS recommendation statement, and multi-specialty peri-operative guidelines as they relate specifically to spine RFA procedures. Results: A total of 197 clinicians participated in the survey from diverse clinical backgrounds, including anesthesiology, physical medicine and rehabilitation, radiology, neurosurgery, and neurology, with 81% reporting fellowship training. Survey responses indicate wide variability in provider management of CIEDs before, during, and after RFA for z-joint pain. Respondents indicated they would like more specific guidelines to aid in management and decision-making around CIEDs and spine RFA procedures. Literature review yielded several practice guidelines related to perioperative management of CIEDs, but no specific guideline for percutaneous spine RFA procedures. However, combining the risk mitigation strategies provided in these guidelines, with interventional pain physician clinical experience allows for reasonable management recommendations to aid in decision-making. Limitations: Although this manuscript can serve as a review of CIEDs and aid in management decisions in patients with CIEDs, it is not a clinical practice guideline. Conclusions: Practice patterns vary regarding CIED management in ambulatory spine RFA procedures. CIED presence is not a contraindication for spine RFA but does increase the complexity of a spine RFA procedure and necessitates some added precautions. Key words: Radiofrequency ablation, neurotomy, cardiac implantable electrical device, zygapophyseal joint, spondylosis, neck pain, low back pain, chronic pain


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