In this paper, we have designed power system stabilizer (PSS) using object-oriented method. There are several types of power system stabilizer, A proportional-integral (PI) controller is very simple for practical implementation. Therefore it has been widely employed by the industry. The methods of obtaining the gains (Ki,Kp) of PI controller are root-locus method and sub-optimal regulator approach. But these methods are cannot be applicable to nonlinear system and faulted power system. So we proposed a new method which can be applied to nonlinear system by numerical analysis method. The method of dynamic system simulation by numerical method is very difficult and complex. We proposed flexible simulation method for complex power system analysis using object-oriented programming (OOP) and applied to PI controller design. (author). 7 refs., 14 figs., 2 tabs.
The topic of supervised learning within the conceptual framework of artificial neural network (ANN) models is addressed. An ANN is a parallel distributed processing system that consists of many computationally simple processing elements interconnected through uni-directional weighted connections. Such networks, which are roughly patterned after biological nervous systems, have been proposed for use in areas in which the traditional von Neumann computer architecture has been relatively unsuccessful. Learning in these networks is accomplished through the use of algorithms that adjust the values of the connection weights. The work presented here addresses the issue of improving the rate at which ANNs can learn to achieve the mapping of an input pattern to a desired output pattern. The most successful learning algorithms for accomplishing this task are based on gradient descent error minimization techniques. However, the large amount of training time that such algorithms require is ...
This paper describes Image Engine, an object-oriented, microcomputer-based, multimedia database designed to facilitate the storage and retrieval of digitized biomedical still images, video, and text...Full Text Available
This paper describes the structure of dynamic neuronal ensembles (DNEs). DNEs represent a new paradigm for learning, based on biological neural networks that use variable structures. We present a computational neural element that demonstrates biological neuron functionality such as neurotransmitter feedback absolute refractory period and multiple output potentials. More specifically, we will develop a network of neural elements that have the ability to dynamically strengthen, weaken, add and remove interconnections. We demonstrate that the DNE is capable of performing dynamic modifications to neuron connections and exhibiting biological neuron functionality. In addition to its applications for learning, DNEs provide an excellent environment for testing and analysis of biological neural systems. An example of habituation and hyper-sensitization in biological systems, using a neural circuit from a snail is presented and discussed. This paper provides an insight into the DNE paradigm ...
The Subseabed Disposal Program has recently completed a 30-day, 0.286-scale laboratory simulation of an In Situ Heat Transfer Experiment (ISHTE), scheduled for eventual deployment in the deep ocean 600 nautical miles north of Hawaii. 10 figures.
The Subseabed Disposal Program has recently completed a 30-day, 0.286-scale laboratory simulation of an In Situ Heat Transfer Experiment (ISHTE), scheduled for eventual deployment in the deep ocean 600 nautical miles north of Hawaii. 10 figures.
This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers. (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users only). (4) ...
This manual describes the use of the Xyce Parallel Electronic Simulator. Xyce has been designed as a SPICE-compatible, high-performance analog circuit simulator, and has been written to support the simulation needs of the Sandia National Laboratories electrical designers. This development has focused on improving capability over the current state-of-the-art in the following areas: (1) Capability to solve extremely large circuit problems by supporting large-scale parallel computing platforms (up to thousands of processors). Note that this includes support for most popular parallel and serial computers; (2) Improved performance for all numerical kernels (e.g., time integrator, nonlinear and linear solvers) through state-of-the-art algorithms and novel techniques. (3) Device models which are specifically tailored to meet Sandia's needs, including some radiation-aware devices (for Sandia users only); and (4) ...
This paper describes a new approach to development of software for highly integrated software-hardware systems such as used for data acquisition and control. This approach, called the ObjectOriented Software Bus (OSB), is a way to develop software according to a common specification similar to the way interface hardware has been developed since the advent of bus structures for minicomputers and microcomputers. Key concept of the OSB is extension of the common use of objects to support user interface and data analysis functions to the development of software objects that directly correspond to real- world hardware interfaces and modules.
The Department of Defense (DoD) has long depended on military support functions enabled by space reconnaissance, surveillance, and target acquisition (RSTA) assets. Future generation satellite capabilities will further push technologies in space - if the right technologies are deployed in the right numbers and with the right payloads. Modeling and simulation play major parts in developing and deploying such assets: 1) system and operational requirements determination, and 2) assessment of military utility of such assets. Each area is critical in a system"s life cycle. Requirements determination cuts across the issues of doctrine, organizations, training, materiel, leader development, personnel, and facilities (DOTMLPF). Military utility assessments are necessary to explore and quantify the military worth/benefit of space RSTA assets to operational commanders. Each of these areas requires relevant ...
Femtocells are assuming an increasingly important role in the coverage and capacity of cellular networks. In contrast to existing cellular systems, femtocells are end-user deployed and controlled, randomly located, and rely on third party backhaul (e.g. DSL or cable modem). Femtocells can be configured to be either open access or closed access. Open access allows an arbitrary nearby cellular user to use the femtocell, whereas closed access restricts the use of the femtocell to users explicitly approved by the owner. Seemingly, the network operator would prefer an open access deployment since this provides an inexpensive way to expand their network capabilities, whereas the femtocell owner would prefer closed access, in order to keep the femtocell's capacity and backhaul to himself. We show mathematically and through simulations that the reality is more complicated for both parties, and that the best approach depends heavily ...
The high spatial resolution of state-of-the-art commercial satellite imagery provides a good basis for recognising and monitoring even small-scale structural changes within nuclear facilities and for planning of routine and/or challenge inspections of nuclear sites. Despite the advantages of the improved spatial resolution some problems exist that may make the interpretation of the changes more difficult: Firstly, the results of the change analysis can be very complex and unclear at a glance. Secondly, shadow formation and off-nadir images due to different sensor and solar conditions at the acquisition times can cause false signals or overlap real changes. In view to the fast-growing amount of data from different sensor types there are then some requirements of an effective change detection procedure for safeguards purposes: i. The techniques involved should possess a certain amount of robustness in terms of small misregistration errors, different atmospheric conditions at the ...
Development and deployment of small-scale nuclear power reactors and their maintenance, monitoring, and control are part of the mission under the Small Modular Reactor (SMR) program. The objectives of this NERI-consortium research project are to investigate, develop, and validate advanced methods for sensing, controlling, monitoring, diagnosis, and prognosis of these reactors, and to demonstrate the methods with application to one of the proposed integral pressurized water reactors (IPWR). For this project, the IPWR design by Westinghouse, the International Reactor Secure and Innovative (IRIS), has been used to demonstrate the techniques developed under this project. The research focuses on three topical areas with the following objectives. Objective 1 - Develop and apply simulation capabilities and sensitivity/uncertainty analysis methods to address sensor deployment analysis and small grid stability issues. Objective 2 - ...
The Two-Column Aerosol Project (TCAP) field campaign will provide a detailed set of observations with which to (1) perform radiative and cloud condensation nuclei (CCN) closure studies, (2) evaluate a new retrieval algorithm for aerosol optical depth (AOD) in the presence of clouds using passive remote sensing, (3) extend a previously developed technique to investigate aerosol indirect effects, and (4) evaluate the performance of a detailed regional-scale model and a more parameterized global-scale model in simulating particle activation and AOD associated with the aging of anthropogenic aerosols. To meet these science objectives, the Atmospheric Radiation Measurement (ARM) Climate Research Facility will deploy the ARM Mobile Facility (AMF) and the Mobile Aerosol Observing System (MAOS) on Cape Cod, Massachusetts, for a 12-month period starting in the summer of 2012 in order to quantify aerosol properties, radiation, and cloud characteristics ...
This paper bundles 40 contributions by the IceCube collaboration that were submitted to the 30th International Cosmic Ray Conference ICRC 2007. The articles cover studies on cosmic rays and atmospheric neutrinos, searches for non-localized, extraterrestrial {nu}{sub e}, {nu}{sub {mu}} and {nu}{sub {tau}} signals, scans for steady and intermittent neutrino point sources, searches for dark matter candidates, magnetic monopoles and other exotic particles, improvements in analysis techniques, as well as future detector extensions. The IceCube observatory will be finalized in 2011 to form a cubic-kilometer ice-Cherenkov detector at the location of the geographic South Pole. At the present state of construction, IceCube consists of 52 paired IceTop surface tanks and 22 IceCube strings with a total of 1426 Digital Optical Modules deployed at depths up to 2350 m. The observatory also integrates the 19 string AMANDA subdetector, that was completed in 2000 and extends ...
"Force20 networks, the pioneer in building and securing reliable networks, today announced that the University of Tennessee physics department has deployed the C300 resilient switch to analyze data form CERN's Large Hadron Collider." (1/2 page)
To treat or prevent some of the 795,000 annual strokes in the U.S., self-expanding endo-vascular stents deployed under fluoroscopic image guidance are often used. Neuro-interventionalists need...Full Text Available
BackgroundVascular stents are small tubular scaffolds used in the treatment of arterial stenosis (narrowing of the vessel). Most vascular stents are metallic and are deployed either...Full Text Available
As part of an investigation of the mechanisms of coastal change in the Carolinas (http://woodshole.er.usgs.gov/project-pages/cccp/index.html), instrumented tripods were deployed on Diamond Shoals near Cape Hatteras, NC. These tripods recorded data quantifying the currents, waves, turbidity, temperat...
hicle [UUV (essentially, a small ex- ploratory submarine robot)] of a type that has been deployed in large numbers in research pertaining to global warm- ...
... geographically flexible rapid- deployment forecasting system that directly leverages the CORIE modeling and information management capabilities. ...
A seaport simulation model, PORTSIM, has been developed for the Department of Defense (DOD) at Argonne National Laboratory. PORTSIM simulates the detailed processes of cargo loading and unloading in a seaport and provides throughput capability, resource utilization, and other important information on the bottlenecks in a seaport operation, which are crucial data in determining troop and equipment deployment capability. There are two key problems to solve in developing the HLA-compliant PORTSIM model. The first is the cargo object ownership transfer problem. In PORTSIM, cargo items, e.g. vehicles, containers, and pallets, are objects having asset attributes. Cargo comes to a seaport for loading or unloading. The ownership of a cargo object transfers from its carrier to the port and then from the port to a new carrier. Each owner of the cargo object is responsible for publishing and updating the attributes of the cargo object ...
Assessing the potential environmental and human effects of deploying renewable energy on private and public lands, along our coasts, on the Outer Continental Shelf (OCS), and in the Great Lakes requires a new way of evaluating potential environmental and human impacts. The author argues that deployment of renewables requires a framework risk paradigm that underpins effective future siting decisions and public policies.
The regular occurrence of large-scale earthquakes in Japan necessitates the use of earthquake disaster prevention systems that focus on gathering damage information on gas supply facilities immediately after an earthquake strikes and minimizing the damage. This paper discussed the development of an earthquake damage estimation system for city gas pipelines that can show damage information in real-time by using earthquake records obtained from densely deployed earthquake observation networks and the most advanced telecommunication and information technologies. The paper summarized the earthquake damage estimation system (EDES) and Toho Gas disaster prevention measures. Specific topics that were discussed included the Toho Gas supply method; earthquake countermeasures; construction of computer systems; normal and emergency operation of EDES; and verification of functions in actual earthquakes. It was concluded that when there is an emergency, the EDES functions as an ...
Verification and validation issues have been perceived as important factors in the large scale deployment of knowledge-based digital systems for plant transient diagnostics and management. Research and development (R&D) is being performed on the IGENPRO package to resolve knowledge base issues. The IGENPRO approach is to structure the knowledge bases on generic thermal-hydraulic (T-H) first principles and not use the conventional event-basis structure. This allows for generic comprehensive knowledge, relatively small knowledge bases and above all the possibility of T-H system/plant independence. To demonstrate concept feasibility the knowledge structure has been implemented in the diagnostic module PRODIAG. Promising laboratory testing results have been obtained using data from the full scope Braidwood PWR operator training simulator. This knowledge structure is now being implemented in the transient management module PROMANA to treat ...
This paper reports on a study to validate the Graphical Network Representation (GRPHREP) model which is being conducted on the Los Alamos National Laboratory Integrated Computer Network (ICN). The GRPHREP model is a software system application based on graph theory and object-oriented programming methodologies. It codified the Department of Energy (DOE) Order 5637.1, which is concerned with classified computer secret policy, restrictions, and requirements. The Los Alamos ICN is required to control access to and support large-scale scientific and administrative computing. Thus, large-scale scientific and administrative computing. Thus we felt that this large, complex, and dynamic network would provide a good test for the graphical and functional capabilities of the model. Furthermore, the ICN is composed of multiple partitions that reflect the sensitivity and classification of the computation (data) and designate the required clearance level for the user.
Geologic sequestration is currently being practiced and scientifically evaluated as a critical component in a broad strategy, comprising new practices and technologies, for mitigating global climate change due to anthropogenic emissions of CO2. Demonstrating that geologic sequestration of CO2 is safe and effective, and gaining public acceptance of sequestration technologies are critically important in meeting these global climate change challenges. Monitored field-scale demonstrations of geologic sequestration of carbon dioxide will contribute greatly toward growing trust and confidence in the technology; however, pilot demonstrations ultimately will not be the norm for new geological sequestration deployments. Instead, scientists, engineers, regulators, and ultimately the public will rely on numerical simulations to predict the performance of geologic repositories for carbon dioxide sequestration. The U.S. Department of Energy (DOE), through ...
... transItion to more capable space-based interceptors as ... ten wtth bmlogtcal, and thirty with chemical weapons. ... are becoming the weapon of choice ...
... second way in which social science dif- fers from the ... it would have been better to leave it intact ... to deploy, returning with worn vessels and sick crews ...
... WHS- Washington Headquarters Service. ... ie, Army, Navy, Air Force) service publications ... The Case of the Rapid Deployment Joint Task Force. ...
... heavy divisions in the Contingency Corps should ... During Operation Desert Shield the 82nd Airborne Division initially deployed a reinforced attack ...
the booms, separated by 12.5 m, deployed using the well proven MILSTAR hinge technology. ...... MILSTAR. Military Strategic and Tactical Relay satellite ...
Sep 5, 1996 ... In Haiti, the military deployed a space support team to advise the task force commander on the effective use of space assets, such as the Milstar ...
BackgroundEnzyme-linked immunosorbent assay (ELISA) is a standard immunoassay to estimate a protein's concentration in a sample. Deploying ELISA in a microarray format permits simultaneous...Full Text Available
A parachute system was designed and prototypes built to deploy a telemetry package behind an earth-penetrating weapon just before impact. The parachute was designed to slow the 10 lb. telemetry package and wire connecting it to the penetrator to 50 fps before impact occurred. The parachute system was designed to utilize a 1.3-ft-dia cross pilot parachute and a 10.8-ft-dia main parachute. A computer code normally used to model the deployment of suspension lines from a packed parachute system was modified to model the deployment of wire from the weapon forebody. Results of the design calculations are presented. Two flight tests of the WBS were conducted, but initiation of parachute deployment did not occur in either of the tests due to difficulties with other components. Thus, the trajectory calculations could not be verified with data. Draft drawings of the major components of the parachute system are ...
... This series of contingency readiness exercises began in July when a company of soldiers from the Army's 82nd Airborne Division deployed to Haiti ...
... Gorman said he broke issues down into three categories: anxiety disorders; pediatric behavioral disorders, such as attention deficit disorder; and ...
California s major energy utilities and the California Energy Commission (CEC) are seeking to allocate capital that yields the greatest return on investment for energy infrastructure that meets any part of the need for reliable supplies of energy. The utilities are keenly interested in knowing the amount of electrical energy savings that would occur if cool roof color materials are adopted in the building market. To meet this need the Oak Ridge National Laboratory and the Lawrence Berkeley National Laboratory (LBNL) have been collaborating on a Public Interest Energy Research (PIER) project to develop an industry-consensus energy-savings calculator. The task was coordinated with an ongoing effort supported by the DOE to develop one calculator to achieve both the DOE and the EPA objectives for deployment of cool roof products. Recent emphasis on domestic building energy use has made the work a top priority by the Department of Energy s (DOE) Building Technologies ...
A population-based, cohort study was conducted to determine the importance of Gulf War deployment to Southwest Asia, from 1 August 1990 to 31 December 1991, in explaining neurologic mortality and peripheral nerve disease among United States military worki...
Middleware deployed to help TCP performance over links with large ... Boeing Connex (Ku-Band); INMARSAT Swift 64; TrackNet" 2.0 (Ku-Band); G2.5/G3/G4. General ... Incremental deployment may be difficult; High Link budgets; Link Delay ...
Institutional issues play a critical, but often overlooked, role in the implementation of renewable energy systems. This paper briefly reviews the institutional arrangements involved in deploying renewable energy from both the sender and receiver perspectives, giving the institutional basis principal characteristics, and pros and cons of each institution. It then offers several perspectives on the critical issues facing the deployment of renewable energy systems before offering a number of potential institutional based solutions. (author)
Integrating technology readiness levels (TRL) into the management of engineering projects is critical to the mitigation of risk and improved customer/supplier communications. TRLs provide a common framework and language with which consistent comparisons of different technologies and approaches can be made. At Sandia National Laboratories, where technologies are developed, integrated and deployed into high consequence systems, the use of TRLs may be transformational. They are technology independent and span the full range of technology development including scientific and applied research, identification of customer requirements, modeling and simulation, identification of environments, testing and integration. With this report, we provide a reference set of definitions for TRLs and a brief history of TRLs at Sandia National Laboratories. We then propose and describe two approaches that may be used to integrate TRLs into the NW SMU business ...
The intention of this study is to show the high potential of remote sensing data to keep an eye on longterm processes in large regions with widespread tasks and questions. The results of two projects (sponsored by the BMBF - Ministry of Education and Science, Germany and the country of Saxony-Anhalt) are taken into account to give an impression of the chances provided by the application of hyperspectral airborne scanner data and satellite images. So these two projects focus at the applicability of various methods to use remote sensing data for a long- term monitoring of former lignite open-cast mining areas. Apart from the traditional pixelorientated analysis, the application and combination of new objectorientated methods (e.g. segmentation, texture analysis) were investigated to distinguish between the following typical vegetation types: Spontaneous revegetation of plant communities; reforestation areas; recultivated grass seeding areas; ...
Comparison of programming languages is a common topic of discussion among software engineers. Few languages ever become sufficiently popular that they are used by more than a few people or find their niche in research or education; but professional programmers can easily use dozens of different languages during their career. Multiple programming languages are designed, specified, and implemented every year in order to keep up with the changing programming paradigms, hardware evolution, etc. In this paper we present a comparative study between ten programming languages: Haskell, Java, Perl, C++, AspectJ, COBOL, Ruby, PHP, Bash Scripts, and Scheme; with respect of the following criteria: Secure programming practices, web applications development, web services design and composition, objectoriented-based abstraction, reflection, aspect-orientation, functional programming, declarative programming, batch scripting, and user interface prototype ...
Clinical-HINTS (Health Intelligence System) is a horizontally integrated decision support system (DSS) designed to meet the requirements for intelligent real-time clinical information management in critical care medical environments and to lay the foundation for the development of the next generation of intelligent medical instrumentation. The system presented was developed to refine and complement the information yielded by clinical laboratory investigations, thereby benefiting the management of the intensive care unit (ICU) patient. More specifically, Clinical-HINTS was developed to provide computer-based assistance with the acquisition, organisation and display, storage and retrieval, communication and generation of real-time patient-specific clinical information in an ICU. Clinical-HINTS is an object-oriented system developed in C+2 to run under Microsoft Windows as an embryo intelligent agent. Current generic reasoning skills include perception and reactive ...
Global meat and milk consumption is exponentially increasing due to population growth, urbanization and changes in lifestyle in the developing world. This is an excellent opportunity for developing countries to improve the livestock sector by using technological advances. Biotechnology is one of the avenues for improved production in the "Livestock revolution". Biotechnology developments applied to livestock health, nutrition, breeding and reproduction are improving with a reasonable pace in developing countries. Simple bio-techniques such as artificial insemination have been well implemented in many parts of the developing world. However, advanced technologies including transgenic plant vaccines, marker assisted selection, solid state fermentation for the production of fibrolytic enzymes, transgenic fodders, embryo transfer and animal cloning are confined largely to research organizations. Some developing countries such as Taiwan, China and Brazil have considered the commercialization ...
This final scientific report documents the Industrial Technology Program (ITP) Stage 2 Concept Development effort on Data Center Energy Reduction and Management Through Real-Time Optimal Control (RTOC). Society is becoming increasingly dependent on information technology systems, driving exponential growth in demand for data center processing and an insatiable appetite for energy. David Raths noted, 'A 50,000-square-foot data center uses approximately 4 megawatts of power, or the equivalent of 57 barrels of oil a day1.' The problem has become so severe that in some cases, users are giving up raw performance for a better balance between performance and energy efficiency. Historically, power systems for data centers were crudely sized to meet maximum demand. Since many servers operate at 60%-90% of maximum power while only utilizing an average of 5% to 15% of their capability, there are huge inefficiencies in the consumption and delivery of power in these data centers. ...
Producing nuclear energy in order to reduce anthropic CO{sub 2} emission and to meet high energy demand, implies three conditions to the nuclear plants of the IV. generation: safety improvements, radioactive waste minimization, and fuel breeding for a sustainable use of the resources. The Thorium fuel cycle used in Molten Salt Reactors seems promising. Many numerical studies based on probabilistic codes are carried out in order to analyse the behaviour of such reactors. Nevertheless, one of the most important parameters is badly known: the alpha ratio of {sup 233}U, ratio of the neutron capture cross section to fission one for {sup 233}U. This key-parameter is necessary to calculate the breeding ratio and thus, the deployment capacities of those reactors. This Ph-D thesis was intended to prepare a precise measurement of the alpha ratio of {sup 233}U between 1 eV and 10 keV. Preliminary measurements have been performed on the experimental platform PEREN. This ...
Cancer is a severe threat to human health. Early detection is considered the best way to increase the chance for survival. While the traditional cancer detection method, biopsy, is invasive, noninvasive optical diagnostic techniques are revolutionizing the way that cancer is diagnosed. Reflectance spectroscopy is one of these optical spectroscopy techniques showing promise as a diagnostic tool for pre-cancer detection. When a neoplasia occurs in tissue, morphologic and biochemical changes happen in the tissue, which in turn results in the change of optical properties and reflectance spectroscopy. Therefore, a pre-cancer can be detected by extracting optical properties from reflectance spectroscopy. This dissertation described the construction of a fiberoptic based reflectance system and the development of a series of modeling studies. This research is aimed at establishing an improved understanding of the optical properties of mucosal tissues by analyzing reflectance signals at ...
The United States deployed 118 military working dogs (MWDs) to the Persian Gulf theater during Operations Desert Shield and Desert Storm. This study is a retrospective descriptive study of medical records of these deployed dogs, with the objective to determine whether there were infectious or parasitic diseases with a zoonotic potential in a sentinel population of MWDs that may be of concern to Persian Gulf veterans. Fifty-one percent of visits to veterinary treatment facilities during deployment were for illness or injury. Potential zoonotic conditions accounted for 21% of the total visits, 41% of the "sick-call" visits, and 63% of presentations for illness to veterinary treatment facilities. This study did not determine whether the diseases treated were transmitted between MWDs and the troops. Although the etiologic agents were not determined in these cases, no evidence was found supporting new or reemerging illnesses in ...
Due to increased deployments with varied missions and new technologies/advanced threats against U.S. Soldiers, a clear need arose for developing camouflage pattern(s) to enhance the Warfighter's survivability' on the modern battlefield. Based on these tec...
A patient is presented with a cervical spinal cord transection which occurred after a motor vehicle accident in which the air bag deployed and the seat belt was not in use. The patient had complete...Full Text Available
Background:The US military is currently involved in large, lengthy, and complex combat operations around the world. Effective military operations require optimal health of deployed...Full Text Available
BackgroundThere is a strong inverse relationship between final vessel diameter and subsequent risk of treatment failure after coronary stent deployment. The aim of this study was...Full Text Available
tion and the Copenhagen symposium in many regards heralded the birth of modern marine bio-optics and the .... given to conducting a pigment intercomparison based on .... assignment of personnel and equipment, so the Hout Bay deployments were suspended. ...... submarine light field. Upwelling radiance is measured at ...
BackgroundMefloquine has historically been considered safe and well-tolerated for long-term malaria chemoprophylaxis, but its prescribing requires careful attention to rule out contraindications...Full Text Available
The economics of renewable energy technologies when deployed in a decentralised manner are more favourable than the simple cost of the fossil fuel generated electricity displaced. They have capital and maintenance cost savings associated with the electrical transmission in infrastructures which are avoided. Worked examples are presented. (UK)
Aluminium (Al3+) toxicity is the primary factor limiting crop production on acidic soils worldwide. In addition to an application of lime for soil amelioration, Al3+ resistant plant varieties have been deployed to raise productivity on such hostile soils. This has been possible due to the exploita...
This Military Working Dog (MWD) was shot in the chest during combat operations in Iraq. Military Working Dogs are critical to the safety and well- being of deployed troops in combat operations and, as such, they are triaged and treated in our combat hospi...
The Fast On-Orbit Recording of Transient Events (FORTE) satellite being built by Los Alamos National Laboratory (LANL) and Sandia National Laboratories (SNL) has as its most prominent feature a large deployable (11 m by 5 m) log periodic antenna to monitor emissions from electrical storms on the Earth. This paper describes the antenna and the design for the long elements and explains the dynamics of their deployment and the damping system employed. It also describes the unique paraffin-actuated reusable tie-down and release mechanism employed in the system.
The endovascular treatment of atherosclerotic intracranial arterial stenoses has previously been based on balloon dilatation or the deployment of a balloon expandable stent. Both methods have advantages (balloon: flexibility; balloon expandable stent: high radial force) and drawbacks (balloon: risk of elastic recoil and dissection; balloon expandable stent: limited flexibility, risk of injury to the vessel due to excessive straightening, overexpansion at ends of stent). A new combination of balloon dilatation, followed by the deployment of a self-expanding microstent has been applied in 15 patients with atherosclerotic arterial stenoses, symptomatic despite medical treatment. An anatomically and clinically adequate result was achieved in all patients. The initial degree of stenosis was 72% (mean). Balloon dilatation resulted in an average residual stenosis of 54% (mean), reduced further to a mean of 38% after stent ...
Connectivity and capacity are two fundamental properties of wireless multi-hop networks. The scalability of these properties has been a primary concern for which asymptotic analysis is a useful tool. Three related but logically distinct network models are often considered in the asymptotic analysis, i.e. the dense network model, the extended network model and the infinite network model, which consider respectively a network deployed in a finite area with a sufficiently large node density, a network deployed in a sufficiently large area with a fixed node density, and a network deployed in $\\Re^{2}$ with a sufficiently large node density. The infinite network model originated from continuum percolation theory and asymptotic results obtained from the infinite network model have often been applied to the dense and extended networks. In this paper, through two case studies related to network connectivity on the expected number ...
Wireless sensor networks can revolutionize soil ecology by providing measurements at temporal and spatial granularities previously impossible. This paper presents a soil monitoring system we developed and deployed at an urban forest in Baltimore as a first step towards realizing this vision. Motes in this network measure and save soil moisture and temperature in situ every minute. Raw measurements are periodically retrieved by a sensor gateway and stored in a central database where calibrated versions are derived and stored. The measurement database is published through Web Services interfaces. In addition, analysis tools let scientists analyze current and historical data and help manage the sensor network. The article describes the system design, what we learned from the deployment, and initial results obtained from the sensors. The system measures soil factors with unprecedented temporal precision. However, the deployment ...
NREL's Solar Advisor Model (SAM) is employed to estimate the current and future costs for parabolic trough and molten salt power towers in the US market. Future troughs are assumed to achieve higher field temperatures via the successful deployment of low melting-point, molten-salt heat transfer fluids by 2015-2020. Similarly, it is assumed that molten salt power towers are successfully deployed at 100MW scale over the same time period, increasing to 200MW by 2025. The levelized cost of electricity for both technologies is predicted to drop below 11 cents/kWh (assuming a 10% investment tax credit and other financial inputs outlined in the paper), making the technologies competitive in the marketplace as benchmarked by the California MPR. Both technologies can be deployed with large amounts of thermal energy storage, yielding capacity factors as high as 65% while maintaining an optimum LCOE.
PurposeThis study evaluates changes in recall of combat exposures over the first year after return from deployment. The research purpose is to assess whether recall of combat exposures is consistent at different time points; if not, what demographic and/or PTSD symptom risk factors exist for any directional instability. MethodsSurveys completed by soldiers at 3, 6, and 12 months post-Operation Iraqi Freedom (OIF) deployment were linked for longitudinal analysis in a previous study in which three matched datasets were created: 3-6 months (N = 768), 6-12 months (N = 341), and 3-12 months (N = 445). Post-traumatic stress disorder (PTSD) was assessed by using the National Center for PTSD Checklist. The reliability of recall for 36 combat exposures was quantified. The effects of demographics an...
Ribbon parachute fabrics were tested during development and production of a 24 ft parachute, and after 2.5 years ambient exposure at several storage sites. The effects of sewing, packing, and parachute deployment on material strength were obtained in the 1000 lb Kevlar ribbon after moisture exposure during packing, and when packed parachutes absorbed moisture or were thermal cycled. Individual yarn samples from the low strength ribbons exhibited little change in strength indicating that the material itself had not degraded. Factors leading to the change in ribbon strength are discussed. Considering all materials, there have been no indications to date of any uncontrollable changes in material strength that would limit the use of Kevlar in parachute applications.
An optimal deployment pattern of flux mapping detectors for a Canada uranium-deuterium (CANDU)-600 pressurized heavy water reactor (PHWR) is determined by obtaining an optimal feedback relationship between flux measurements and zone controllers. The reactor core is modeled with a time-dependent two-group, two-dimensional diffusion equation, and flux perturbation are expressed by model expansions. The modal expansion coefficients are used as elements of the state vector representing the system dynamics. An optimal feedback matrix connecting the flux measurement vector to the control vector is derived by minimizing a quadratic performance index involving both the state and control vectors. We obtain the detector effectiveness in terms of the optimal feedback matrix and determine optimal detector locations for the Wolsung Unit 1 reactor in Korea. We have tested the methodology through evaluation of flux maps generated through the CANDU flux mapping system.
Over three years ago, the Core Integration team of the National Science Digital Library (NSDL) implemented a digital library based on metadata aggregation using Dublin Core and OAI-PMH. The initial expectation was that such low-barrier technologies would be relatively easy to automate and administer. While this architectural choice permitted rapid deployment of a production NSDL, our three years of experience have contradicted our original expectations of easy automation and low people cost. We have learned that alleged "low-barrier" standards are often harder to deploy than expected. In this paper we report on this experience and comment on the general cost, the functionality, and the ultimate effectiveness of this architecture.
Current Intrusion Detection System (IDS) technology is not suited to be widely deployed inside a Supervisory, Control and Data Acquisition (SCADA) environment. Anomaly- and signature-based IDS technologies have developed methods to cover information technology-based networks activity and protocols effectively. However, these IDS technologies do not include the fine protocol granularity required to ensure network security inside an environment with weak protocols lacking authentication and encryption. By implementing a more specific and more intelligent packet inspection mechanism, tailored traffic flow analysis, and unique packet tampering detection, IDS technology developed specifically for SCADA environments can be deployed with confidence in detecting malicious activity.
This report presents the findings of a U.S. DOE Environmental Management technology transfer initiative of waste-reducing ground water sampling systems between Savannah River Site (SRS) and Lawrence Livermore National Laboratory (LLNL) which occurred during fiscal years 2001 and 2002. The report describes the collaboration between the two sites, the deployment of the Savannah River Site Purge Water Management System at LLNL, the changes made to that system for use at LLNL, and documents the return-on-investment derived from the system's use at LLNL as well as other benefits generated through this inter-laboratory collaboration. An evaluation of the deployment of the LLNL EasyPump sampling technology at SRS will be covered in a separate report from SRS.
Concept Exploration (CE) experiments within the Innovative Confinement Concept Program have a unique role which impacts their contributions to the development of fusion energy. As stated in the FESAC ''Report on Alternate Concepts:'' These [CE] programs are aimed at innovation and basic understanding of relevant scientific phenomena. The emphasis on innovation motivates their application to the search for a better fusion reactor configuration. In addition, because of their unique character the CE experiments offer excellent opportunities to couple fusion-plasma physics to other sciences. A recent example of coupling is the fusion self-organized plasmas to reconnection physics and extra-terrestrial plasmas. Perhaps of even greater importance is the education of the future scientists needed for developing fusion energy. The CE experiments, both at universities and national labs, are of a size students can ''get their hands ...
The following paragraphs summarize the progress of each research project funded under the WVU Cooperative Agreement during the third quarter of 1997 (July - September 1997). The projects are arranged according to their 1997 WVU task number. WVU Focus Area 1.0: Subsurface Contaminants, Containment and Remediation Task No. 1.1: Project discontinued. Task No. 1.2: Development of Standard Test Protocols and Barrier Design Models for Desiccation Barriers (K. Amininan & S. Ameri): A number of experiments were preformed this period to evaluate the ability of the dried sand-packs to act as a barrier to liquids. Water infiltration tests were done with a constant head, dispersing 80 ml of water, and by adding water in small increments. Results indicate that when the water is spilled over the sand-pack, it has the tendency to channel through the sand-pack, significantly reducing the capacity of the dried zone to retain liquid contaminants. This appears to be largely influenced by particle ...
Aircraft constitute a unique environment which places stringent requirements on the instruments used to measure the concentrations of atmospheric trace gases and aerosols. Some of these requirements such as minimization of size, weight, and power consumption are general; others are specific to individual techniques. This review presents the basic principles and considerations governing the deployment of trace gas and aerosol instrumentation on an aircraft. An overview of common instruments illustrates these points and provides guidelines for designing and using instruments on aircraft-based measurement programs.
... April 29, 2011, 8:25 AM PDT | By Andrew Nusca Ottawa taps Itron for 210,000 smart water meters The City of Ottawa has chosen smart grid firm Itron ...to deploy smart water meters and related infrastructure in town. April 29, 2011, 7:18 AM PDT | By Andrew ...
Objective: To evaluate technical feasibility and acute and subacute radiotolerance of a self-expandable stent loaded with {sup 125}I seeds in the rabbit esophagus. Methods: A self-expandable stent designed for esophageal application was made of 0.16 mm nitinol wire and loaded with {sup 125}I seeds (CIAE-6711). Twenty-seven stents with three different radioactive dosages (n = 9 in each dosage group) were implanted in the esophagus of healthy rabbits, while nine stents alone were used as controls. The stents were perorally deployed into the esophagus under fluoroscopic guidance. Radiological follow-up included plain chest film, CT scan, and barium esophagography which were undertaken in all rabbits of each group at 2, 4, and 8 weeks, respectively, which were correlated to histopathological findings. The stented esophageal segments along with their adjacent tissues were harvested for histopathological examinations. Results: The stent was successfully ...
The solar array wings were deployed by swinging two half-blanket boxes open from a folded hinge launch position .... pure-water by-product of the shuttle's fuel cell power generators because ..... outgassing limits, flammability limits, ... Foale fills a water microbiology bag for in-flight analysis. ...
In an effort to accelerate deployment of Distributed Energy Resources (DER) such as wind, solar, and conventional backup generators to our nation's electrical grid, Northern Power Systems (NPS), the California Energy Commission (CEC), and the National Renewable Energy Laboratory (NREL) collaborated to create a prototype universal interconnect device called the DER Switch.
The present report outlines the background and issues supporting the national strategy which was developed to deploy U.S. Government resources most effectively to increase environmental technologies exports and to enhance the trade competitiveness of the U.S. environmental technologies sector. The document is a supplement to the strategic framework.
Femtocell is emerging as a key technology to secure the coverage and capacity in indoor environments. However the deployment of a new femtocell layer may originate undesired interference to the whole system. This paper investigates spectrum resource coordination and interference management for the femtocell networks. A resource coordination scheme based on broadcasting resource coordination request messages by the femto mobile is proposed to reduce the system interference.
In the framework of a global analysis of the various available sources of energy, Japan has reserved a prominent place to the nuclear energy, and in the long-term view, to the breeder reactor which will be due for commercial deployment in 2010. To achieve these objectives, three stages are envisaged, one of the experimental reactor Joyo (in service), one of the demonstration reactor Monju (its construction has been decided), and one of the pre-commercial reactor (due to be taken in hand at the beginning of the Nineties). Efforts will be made in parallel concerning the fuel cycle.
This paper surveys the growing number of industrial applications of data mining and knowledge discovery. We look at the existing tools, describe some representative applications, and discuss the major issues and problems for building and deploying successful applications and their adoption by business users. Finally, we examine how to assess the potential of a knowledge discovery application.
The fundamental optical absorption of ion crystals characterizes the creation of different free low energetic electronic excitation (the excitons and electron-hole pairs), but their straight registration is not possible because of incommensurable big absorption factor of alkali halide monocrystals. So to registration the spectrums of alkali halide monocrystal very fine layers are necessary. We have received fine films of Nal and KCl in system of KCl-Nal-KCl, KCl-KI-KCl on the base of universal vacuum post VUP-4, VUP-5 by thermal evaporation. A unique spectral unit has been created For this on the basic the SDL-2 complex. Complex consists of radiator, systems of condensers, monochromators MDR-12 and MDR-23, receivers of radiation, controller by unit. Connect and control of monochromators by means of IBM-compatible computer has been created. Kinematics schemes of monochromators provide consequent removing on output slot of monochromatic radiation in operating range of each diffraction ...
This series of animations depicts the results of a computer simulation of the effects of deforestation on the surface temperature and precipitation in the Amazon region. Six animations are shown - a control simulation, a deforestation simulation, and the difference between the two for both surface temperature and rainfall. The period simulated is the second half of 1987.
... DARPA UUV and the UUV support simulator. ... Modular connections for robot arm manipulators ... Intelligent mobile robots will be performing many ...
'Full text:' Deregulation, distributed generation, combined heat and power, renewables, fuel cells, hydrogen. Power companies are facing a rapidly evolving environment that is testing their ability to effectively deploy capital and earn profits. While recent deregulation trends have shifted the structure of power markets into separating generators from distributors, the improving economic value proposition offered by smaller scale distributed generation technologies - such as fuel cells - would seem to be a conflicting development. In this complex and changing environment, decisions based on the economic reality of the capital markets are likely to prevail. By examining the opportunity to enhance risk management offered by stationary fuel cells, particularly in CHP applications, we provide a context for the issues being discussed in today's sessions focusing on power companies and electric utilities. Our risk management perspective suggests a pathway for ...
CANDU steam generators and heat exchangers have been afflicted with a significant variety of degradation mechanisms. Until recently, detection and characterization of most of the varieties of flaws required usage of several different eddy current techniques. Tubes needed to be scanned multiple times to ensure they were inspected for all possible degradation mechanisms. The time required to deploy so many different types of techniques to inspect the steam generator tubes has had a significant impact on the inspection schedules. The X-Probe was designed with an array of eddy current coils capable of detecting, characterizing and sizing axial, circumferential and volumetric flaws. The X-Probe is a fast-scanning probe with scanning speed equivalent to speeds typically used for simple bobbin coil probes. With its capability of fulfilling most if not all of the functions of the other tube-testing eddy current probes, it can inspect each tube for all degradation ...
CANDU steam generators and heat exchangers have been afflicted with a significant variety of degradation mechanisms. Until recently, detection and characterization of most of the varieties of flaws required usage of several different eddy current techniques. Tubes needed to be scanned multiple times to ensure they were inspected for all possible degradation mechanisms. The time required to deploy so many different types of techniques to inspect the steam generator tubes has had a significant impact on the inspection schedules. The X-Probe was designed with an array of eddy current coils capable of detecting, characterizing and sizing axial, circumferential and volumetric flaws. The X-Probe is a fast-scanning probe with scanning speed equivalent to speeds typically used for simple bobbin coil probes. With its capability of fulfilling most if not all of the functions of the other tube-testing eddy current probes, it can inspect each tube for all degradation ...
High and volatile natural gas prices have increasingly led to calls for investments in renewable energy. One line of argument is that deployment of these resources may lead to reductions in the demand for and price of natural gas. Many recent US-based modeling studies have demonstrated that this effect could provide significant consumer savings. In this article we evaluate these studies, and benchmark their findings against economic theory, other modeling results, and a limited empirical literature. We find that many uncertainties remain regarding the absolute magnitude of this effect, and that the reduction in natural gas prices may not represent an increase in aggregate economic wealth. Nonetheless, we conclude that many of the studies of the impact of renewable energy on natural gas prices appear to have represented this effect within reason, given current knowledge. These studies specifically suggest that a 1% reduction in US natural gas demand could lead to ...
High and volatile natural gas prices have increasingly led to calls for investments in renewable energy. One line of argument is that deployment of these resources may lead to reductions in the demand for and price of natural gas. Many recent US-based modeling studies have demonstrated that this effect could provide significant consumer savings. In this article we evaluate these studies, and benchmark their findings against economic theory, other modeling results, and a limited empirical literature. We find that many uncertainties remain regarding the absolute magnitude of this effect, and that the reduction in natural gas prices may not represent an increase in aggregate economic wealth. Nonetheless, we conclude that many of the studies of the impact of renewable energy on natural gas prices appear to have represented this effect within reason, given current knowledge. These studies specifically suggest that a 1% reduction in US natural gas demand could lead to ...
The goal of this LDRD was to demonstrate the use of robotic vehicles for deploying and autonomously reconfiguring seismic and acoustic sensor arrays with high (centimeter) accuracy to obtain enhancement of our capability to locate and characterize remote targets. The capability to accurately place sensors and then retrieve and reconfigure them allows sensors to be placed in phased arrays in an initial monitoring configuration and then to be reconfigured in an array tuned to the specific frequencies and directions of the selected target. This report reviews the findings and accomplishments achieved during this three-year project. This project successfully demonstrated autonomous deployment and retrieval of a payload package with an accuracy of a few centimeters using differential global positioning system (GPS) signals. It developed an autonomous, multisensor, temporally aligned, radio-frequency communication and signal processing capability, ...
The Daya Bay reactor neutrino experiment is located at the Daya Bay nuclear power plant in Shenzhen, China. The experiment deploys eight 'identical' antineutrino detectors to measure antineutrino fluxes from six 2.9 GWth reactor cores in three underground experimental halls at different distances. The target zone of the Daya Bay detector is filled with 20 t 0.1% Gd doped LAB liquid scintillator. The baseline uncorrelated detector uncertainty is ?0.38% using current experimental techniques. Daya Bay can reach a sensitivity of sin22?13<0.01 with baseline uncertainties after 3 years of data taking.
The technology developed here will exploit the ability of microorganisms to remove dissolved metals from aqueous solutions. Microbial sorbents for uranium will be immobilized biosorbents will be deployed ex situ within flow-through reactors for the continuous or semicontinuous treatment of recovered wastewaters. The proposed technology will primarily be applied within a pump-and-treat process using immobilized biosorbents for the large-scale, long-term remediation of uranium-laden surface water or groundwater impoundments (environmental restoration). The technology may be equally useful as an ``end-of-pipe`` treatment of process effluents (waste management). Successful operation of this process will achieve immobilization of the targeted waste and accompanying volume reduction.
This paper presents a framework for creating a common spatial canvass that can bring together considerations of resource availability, infrastructure reliability, and development costs while strategizing renewable energy investment. We describe the underlying models and methodologies that annotate an investment plan for potential sites over a time-period with costs and constraints which may be imposed on distance from infrastructure, system impact on infrastructure, and policy incentives. The framework is intended as an enabler for visualization, optimization and decision making across diverse dimensions while searching for lucrative investment-plans.
Central nervous system (CNS) development, homeostasis, stress responses, and plasticity are all mediated by epigenetic mechanisms that modulate gene expression and promote selective deployment of functional gene networks in response to complex profiles of interoceptive and environmental signals. Thus, not surprisingly, disruptions of these epigenetic processes are implicated in the pathogenesis of a spectrum of neurological and psychiatric diseases. Epigenetic mechanisms involve chromatin remodeling by relatively generic complexes that catalyze DNA methylation and various types of histone modifications. There is increasing evidence that these complexes are directed to their sites of action by long non-protein-coding RNAs (lncRNAs), of which there are tens if not hundreds of thousands speci...
The marine ram-type blowout preventer deployed from an offshore drilling rig has one serious disadvantage, its inaccessibility. A development to promote reliability of the subsea ram-type preventer and reduce the excess running and pulling to charge out rams, is the variable bare ram (VBR). Unlike the standard ram, the VBR has the ability to pack off a range of pipe sizes. Interest in VBR's has been revived and research and development in this equipment goes on at each of three manufacturer's facilities in Houston.
Inspire is the project name of a new High Energy Physics information system which will integrate present databases and repositories to host the entire corpus of the HEP literature and become the reference HEP scientific information platform worldwide. It is a common project between CERN, DESY, FERMILAB and SLAC. It will empower scientists with new tools to discover and access the results most relevant to their research; enable novel text- and data-mining applications; deploy new metrics to assess the impact of articles and authors. In addition, it will introduce the Web2.0 paradigm of user-enriched content in the domain of sciences with community-based approaches to the peer-review process.
Having always been at the forefront of information management and open access, High-Energy Physics (HEP) proves to be an ideal test-bed for innovations in scholarly communication including new information and communication technologies. Three selected topics of scholarly communication in High-Energy Physics are presented here: A new open access business model, SCOAP3, a world-wide sponsoring consortium for peer-reviewed HEP literature; the design, development and deployment of an e-infrastructure for information management; and the emerging debate on long-term preservation, re-use and (open) access to HEP data.
This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.
This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.
To support the Space Exploration Initiative (SEI), a study was performed to investigate power system alternatives for the rover vehicles and servicers that were subsequently generated for each of these rovers and servicers, candidate power sources incorporating various power generation and energy storage technologies were identified. The technologies were those believed most appropriate to the SEI missions, and included solar, electrochemical, and isotope systems. The candidates were characterized with respect to system mass, deployed area, and volume. For each of the missions a preliminary selection was made. Results of this study depict the available power sources in light of mission requirements as they are currently defined.
A major objective of the DOE Advanced Fuel Cycle Initiative, AFCI, is to explore technologies that may reduce the long-term environmental burden of nuclear energy through more efficient disposal of waste materials. In this work, the potential impact of the AFCI technology and its beneficial effects on waste management and its ability to meet waste management objectives are demonstrated. In addition, practical scenarios to improve permanent disposal utilization and/or reduce the temporary spent nuclear fuel (SNF) storage inventory by closing the fuel cycle through transition to fast reactor (FR) converters are also discussed. (authors)
The insertion of innovative technologies to replace baseline technologies used in cost estimation and planning of DOE D&D projects is considered a high risk endeavor by project and programmatic decision makers. It is almost always considered safer to go with the {open_quotes}devil you know{close_quotes} than use a new or untried technology, methodology or system. The decision on the specific technology to be utilized to remediate a problem is often made months or years in advance of execution, and the highly proscriptive documentation of agreements necessary to obtain stakeholder and regulator approval of remedial plans is often counterproductive to considering improved technologies.
Unmanaged pollutants from putrescible farm, industrial, and municipal wastes degrade in the environment, and methane emitted from their decomposition may contribute to global climate change. Under modern environmental regulations, these wastes are becoming difficult to dispose of using traditional means. One waste management system, anaerobic digestion or AD, not only provides pollution prevention but can also convert a disposal problem into a new profit center. This report is drawn from a special session of the Second Biomass Conference of the Americas. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.
This paper experimentally evaluates the effects of applying autonomic management to the scheduling of maintenance operations in a deployed Chord network, for various membership churn and workload patterns. Two versions of an autonomic management policy were compared with a static configuration. The autonomic policies varied with respect to the aggressiveness with which they responded to peer access error rates and to wasted maintenance operations. In most experiments, significant improvements due to autonomic management were observed in the performance of routing operations and the quantity of data transmitted between network members. Of the autonomic policies, the more aggressive version gave slightly better results.
We develop methods for accelerating metric similarity search that are effective on modern hardware. Our algorithms factor into easily parallelizable components, making them simple to deploy and efficient on multicore CPUs and GPUs. Despite the simple structure of our algorithms, their search performance is provably sublinear in the size of the database, with a factor dependent only on its intrinsic dimensionality. We demonstrate that our methods provide substantial speedups on a range of datasets and hardware platforms. In particular, we present results on a 48-core server machine, on graphics hardware, and on a multicore desktop.
Fermilab is the US Tier-1 Center for CMS data storage and analysis. End-2-End (E2E) circuits are utilized to support high impact data movement into and out of the Tier-1 Center. E2E circuits have been implemented to facilitate the movement of raw experiment data from the Tier-0 Center at CERN, as well as processed data to a number of the US Tier-2 sites. Troubleshooting and monitoring of those circuits presents a significant challenge, since the circuits typically cross multiple research & education networks, each with its own management domain and customized monitoring capabilities. The perfSONAR Monitoring Project was established to facilitate development and deployment of a common monitoring infrastructure across multiple network management domains. Fermilab has deployed perfSONAR across its E2E circuit infrastructure and enhanced the product with several tools that ease the monitoring and management of those circuits. This paper will ...
The authors review two types of simulators for the analysis of cosmic ray neutron-induced soft errors (SE's). One of them is the neutron-induced soft error simulator (NISES). A recently proposed nuclear reaction theory forms the foundation for the nuclear reaction database used in NISES. The other simulator, the simplified simulator MBGR, is based on a modified version of the burst generation rate (BGR) model. Both simulators accurately simulate neutron-induced SE rates (SER's). MBGR actually provides an easier and quicker estimation of neutron-induced SER's than NISES. On the other hand, NISES covers more applications; it simulates neutron-induced charge collection, multiple-bit SE, and [alpha]-induced SE analysis.
The authors review two types of simulators for the analysis of cosmic ray neutron-induced soft errors (SE's). One of them is the neutron-induced soft error simulator (NISES). A recently proposed nuclear reaction theory forms the foundation for the nuclear reaction database used in NISES. The other simulator, the simplified simulator MBGR, is based on a modified version of the burst generation rate (BGR) model. Both simulators accurately simulate neutron-induced SE rates (SER's). MBGR actually provides an easier and quicker estimation of neutron-induced SER's than NISES. On the other hand, NISES covers more applications; it simulates neutron-induced charge collection, multiple-bit SE, and #alpha#-induced SE analysis
A special purpose hardware machine, which simulates up to one half-million gates and 2m byte RAM ICS at a 5 millisecond clock speed is described. This is accomplished with a hardware logic (HAL) simulator. This performance is achieved with 32 distributed special parallel processors, which utilize block oriented simulation technique. The technique promises a good cost hardware logic simulator. 7 references.
A computer program 'CPA simulator' has been designed to simulate the response parameters of a typical charge preamplifier (CPA) used in nuclear front-end electronics. The response parameters are studied considering three common connection methods between the detector and the CPA. The simulator predicts and illustrates the role and influence of the different components of the CPA and detector circuits.
Waveform correlation detectors compare a signal template with successive windows of a continuous data stream and report a detection when the correlation coefficient, or some comparable detection statistic, exceeds a specified threshold. Since correlation detectors exploit the fine structure of the full waveform, they are exquisitely sensitive when compared to power (STA/LTA) detectors. The drawback of correlation detectors is that they require complete knowledge of the signal to be detected, which limits such methods to instances of seismicity in which a very similar signal has already been observed by every station used. Such instances include earthquake swarms, aftershock sequences, repeating industrial seismicity, and many other forms of controlled explosions. The reduction in the detection threshold is even greater when the techniques are applied to arrays since stacking can be performed on the individual channel correlation traces to achieve significant array gain. In previous ...
A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wi...
The impacts of climate change on crop productivity are often assessed using simulations from a numerical climate model as an input to a crop simulation model. The precision of these predictions reflects...Full Text Available
Computer simulations of agricultural finance and management may be helpful to students preparing for agricultural careers. Simulations would provide problem definition and problem solving in realistic interactions with complex and ambiguous situations similar to those encountered in farming. The paper describes a major financial problem for farmers, explores the implications of that problem for students, and outlines a computer-based simulation model which would give students experience in dealing with the problem. Data sources for simulations, potentials of interactive exercises among students, and advantages of using real data with existing ambiguities are described. The board game "AGRICULTURE" is discussed as a prototype for simulation. (LFL)
This paper presents an approach to comparing computer run time of building simulation programs. The computing run time of a simulation program depends on several key factors, including the calculation algorithm and modeling capabilities of the program, the run period, the simulation time step, the complexity of the energy models, the run control settings, and the software and hardware configurations of the computer that is used to make the simulation runs. To demonstrate the approach, simulation runs are performed for several representative DOE-2.1E and EnergyPlus energy models. The computer run time of these energy models are then compared and analyzed.
Sep 1, 2011 ... 2005. Computer simulation modeling of recreation use: current status, case studies, and future directions. Gen. Tech. Rep. RMRS-GTR-143. ...
An application that provides a flexible and easy to use interface to the GAMMA spectral simulation package is described that is targeted at investigations using in vivo MR spectroscopic methods....Full Text Available
Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that the performance of ...
The Heard Island Feasibility Test (HIFT) demonstrated that coded acoustic signals could be detected at ranges up to 18,000 km with currently available source technology. This paper describes one component of the HIFT where a large aperture vertical line array was deployed to record the signals transmitted from Heard Island. We have performed four analysis Of the VLA receptions, of the Heard Island signals. All four suggest the presence of higher order modes. The frequency- vertical wavenumber analysis and the modal beamforming indicate that mode 3 has the highest amplitude while the modal fitting suggests that made 5--6 are largest. It is difficult to resolve the differences since the SNR at the VLA, nearly 18,000 km with a transmission loss of around 145 dB, is quite low. Individual arrivals could not be distinguished because of the long integration time necessitated by the low SNR.
This presentation gives an overview of IBM's experience with its approach to usability engineering, User-Centered Design (UCD), which has been introduced nearly one decade ago. It discusses the characteristics of User-Centered Design and the critical factors for successful deployment: - Establishing a culture for usability engineering. - Making User-Centered Design an integral part of the development process. - Multi-disciplinary teams for the design and evaluation of the total user experience. - Building up organizational structures and an infrastructure for methods, tools, communication, and education. - Applying UCD to UCD itself to continuously improve its process and methods. (orig.)
The TVR heavy water research reactor was deployed at Moscow Institute of Theoretical and Experimental Physics. In 1990, the final batch of the spent nuclear fuel from this reactor was shipped to Production Association (PA) 'Mayak' for reprocessing. The SNF removal was a stage of the reactor decommissioning activities. The designs of the TVR reactor and its fuel elements are similar to the RA reactor designs. Two ways of the RA reactor SNF transportation to PA 'Mayak' have been considered: in aluminum barrels and in additional canisters using respectively TUK-32 and TUK-19 shipping casks. The practical experience and the equipment used to prepare for the TVR reactor SNF removal can be helpful to the RA reactor personnel in finding the best way to perform these engineering operations. (author)
In the insurance industry, spreadsheets have emerged as an invaluable tool to for product pricing, because it is relatively straightforward to create and maintain complex pricing models using Excel. In fact, Excel is often preferred to "hard-code" whenever there are frequent changes to the calculations and business logic which under-pin the pricing of an insurance product. However, problems arise as soon as spreadsheets are deployed to end-users: version control, security of intellectual property, and ensuring correct usage are obvious issues; frequently, integration with other systems is also a requirement. Zurich Financial Services Group is a leading financial services provider; several possible solutions to these problems have been evaluated, and EASA has been selected as the preferred technology. Other spreadsheet collaboration approaches which were considered include Excel Services, and/or custom-built software; however, EASA has provided clear benefits over ...
AIM: The purpose of the study was to evaluate the percutaneous use of the new nitinol SMARTeR stents in patients with biliary obstruction. MATERIALS AND METHODS: Four stents were placed in three patients percutaneously under ultrasound and fluoroscopic guidance. RESULTS: The deployment of the stents was successful in all three patients. All stents maintained their patency and position after short-term follow-up. CONCLUSION: The nitinol SMARTeR stent is useful in the management of patients with biliary obstruction although accurate placement across the ampulla was found to be technically more difficult than with the Wallstent. Larger, long-term follow-up studies are required to evaluate the long-term patency of these new devices.
Effective integration of nonproliferation management into the design process is key to the broad deployment of advanced nuclear energy systems, and is an explicit goal of the Laser Inertial Fusion Energy (LIFE) project at Lawrence Livermore National Laboratory. The nuclear explosives utility of a nuclear material to a state (proliferator) or sub-state (terrorist) is a critical factor to be assessed and is one aspect of material attractiveness. In this work, we approached nuclear explosives utility through the calculation of a ''figure of merit'' (FOM) that has recently been developed to capture the relative viability and difficulty of constructing nuclear explosives starting from various nuclear material forms and compositions. We discuss the integration of the figure of merit into an asse...
Background: Healthcare providers and their IT staff, working in an effort to balance appropriate accessibility with stricter security mandates, are considering the use of a single network sign-on approach for authentication and password management. Single sign-on (SSO) promises to improve usability of authentication for multiple-system users, increase compliance, and help curb system maintenance costs. However, complexities are introduced when SSO is placed within a collaborative environment. These complexities include unanticipated workflow implications that introduce greater security vulnerability for the individual user. Objectives and methodology: In this work, we examine the challenges of implementing a single sign-on authentication technology in a hospital environment. The aim of the...
This document presents a summary of the work performed in support of the Buried Waste Robotics Program Subsurface Mapping Project. The project objective was to demonstrate the feasibility of remotely characterizing buried waste sites. To fulfill this objective, a remotely-operated vehicle, equipped with several sensors, was deployed at the Idaho National Engineering Laboratory. Descriptions of the equipment and areas involved in the project are included in this report. Additionally, this document provides data that was obtained during characterization operations at the Cold Test Pit and the Subsurface Disposal Area, both at the Idaho National Engineering Laboratory's Radioactive Waste Management Complex, and at the Idaho Chemical Processing Plant. The knowledge gained from the experience, that can be applied to the next generation remote-characterization system, is extensive and is presented in this report.
Purpose - The service-dominant (S-D) logic views supply chains as value co-creation networks. These networks promote knowledge growth amongst network members via resource deployment and coordination. The exchange of knowledge and utilization of operant resources among the network members leads to co-created service offerings and value proposals for the end-users, with the ultimate goal of transforming end-user experiences to perceptions of superior value-in-use. The purpose of this paper is to develop an illustration of the value co-creation concept and use this illustration as guide to examine the research gaps that are yet to be tapped in the area where supply chain networks and S-D logic intersects. Design/methodology/approach - The literature on S-D logic is reviewed and research gaps ...
The author considers the possibility that Japanese nuclear armament might be a realistic political option. Firstly introducing various issues on Japanese nuclear armament existing since long time ago, he classifies them according to the view point from internal and international problems. Internally, the armament is not possible at present on the ground of the nation's non-nuclear policy but it might be conditionally a choice in such case as the reliability of US nuclear deterrence declines or possibility of nuclear attack to Japan actually may be predicted. The armament may be possible technically and legally based on the consensus of the people. Various concerns by neighboring countries are discussed. Finally, the author stresses the importance of continuing to consolidate bilateral relationship with US, to deploy missile defensive system and to make every effort in the diplomatic activity for strong international ties and cooperation. (S. Ohno)
RFID technology is gaining adoption on an increasing scale for tracking and monitoring purposes. Wide deployments of RFID devices will soon generate an unprecedented volume of data. Emerging applications require the RFID data to be filtered and correlated for complex pattern detection and transformed to events that provide meaningful, actionable information to end applications. In this work, we design and develop SASE, a com-plex event processing system that performs such data-information transformation over real-time streams. We design a complex event language for specifying application logic for such transformation, devise new query processing techniques to effi-ciently implement the language, and develop a comprehensive system that collects, cleans, and processes RFID data for deliv-ery of relevant, timely information as well as storing necessary data for future querying. We demonstrate an initial prototype of SASE through a real-world retail management ...
Today, component oriented middlewares are used to design, develop and deploy easily distributed applications, by ensuring the heterogeneity, interoperability, and reuse of the software modules, and the separation between the business code encapsulated in the components and the system code managed by the containers. Several standards answer this definition such as: CCM (CORBA Component Model), EJB (Enterprise Java Beans) and .Net. However these standards offer a limited and fixed number of system services, removing any possibility to add system services or to reconfigure dynamically the middleware. Our works propose mechanisms to add and to adapt dynamically the system services, based on a reconfiguration language which is dynamically adaptable to the need of the reconfiguration, and on a tool of dynamic reconfiguration, a prototype was achieved for the OpenCCM platform, that is an implementation of the CCM specification. This work was partially financed by the ...
The goal of this three-year project was to improve the production systems in use by steel foundries in the United States. Improvements in the production systems result in less rework, less scrap, and less material handling, all of which would significantly reduce the energy demands of the process. Furthermore, these improvements would allow the companies to be more competitive, more responsive to customers' needs, deliver products with less lead time and require less capital. The ultimate result is a stronger domestic steel casting industry, which uses less energy. A major portion of this research involved the deployment of student researchers at steel foundries, to study their production systems and collect data.
This report summarizes the activities carried out by Aspen Systems Corporation in support of the Department of Energy's Rebuild America program during the period from October 9, 1999 to October 31, 2004. These activities were in accordance with the Scope of Work contained in a GSA MOBIS schedule task order issued by the National Energy Technology Laboratory. This report includes descriptions of activities and results in the following areas: deployment/delivery model; program and project results; program representative support activities; technical assistance; web site development and operation; business/strategic partners; and training/workshop activities. The report includes conclusions and recommendations. Five source documents are also provided as appendices.
Many existing proposals either lack sufficient concreteness to make carbon capture and geological sequestration (CCGS) operational or fail to focus on a comprehensive, long term framework for its regulation, thus failing to account adequately for the urgency of the issue, the need to develop immediate experience with large scale demonstration projects, or the financial and other incentives required to launch early demonstration projects. We aim to help fill this void by proposing a roadmap to commercial deployment of CCGS in the United States.This roadmap focuses on the legal and financial incentives necessary for rapid demonstration of geological sequestration in the absence of national restrictions on CO2 emissions. It weaves together existing federal programs and financing opportunities into a set of recommendations for achieving commercial viability of geological sequestration.
Floating production storage and offloading (FPSO) vessels offer a cost-effective field development solution, especially in deepwater areas lacking an adequate pipeline network. Most FPSOs are permanently moored, i.e. the complete system is designed to withstand any kind of extreme environment at the field location. FPSOs that can be quickly disconnected from their moorings and risers have also been designed and deployed. The key feature of this type of disconnectable FPSO is that it can be disconnect and so avoid dangerous environmental conditions such as icebergs, hurricanes in the Gulf of Mexico and typhoons in the South China Sea. In this paper, the concept of disconnectable FPSOs for deepwater field development is presented. Key technologies and their engineering analyses are highlight...
Implementing any new business software can be an intimidating prospect and this paper is intended to offer some insight in to how to approach this challenge with some fundamental rules for success. Los Alamos National Laboratory (LANL) had undergone an original ERP implementation of HRMS, Oracle Advanced Benefits, Worker Self Service, Manager Self Service, Project Accounting, Financials and PO, and recently completed a project to implement Oracle Payroll, Time and Labor and Accrual Plans. This paper will describe some of the important lessons that can be applied to any implementation as a whole, and then specifically how this knowledge was applied to the design and deployment of Oracle Accrual Plans for LANL. Finally, detail on the functionality available in Oracle Accrual Plans will be described, as well as the detailed setups.that were utilized at LANL.
Integrated femtocell/macrocell networks, comprising a conventional cellular network overlaid with femtocells, offer an economically appealing way to improve coverage, quality of service, and access network capacity. The key element to successful femtocells/macrocell integration lies in its self-organizing capability. Provisioning of quality of service is the main technical challenge of the femtocell/macrocell integrated networks, while the main administrative challenge is the choice of the proper evolutionary path from the existing macrocellular networks to the integrated network. In this article, we introduce three integrated network architectures which, while increasing the access capacity, they also reduce the deployment and operational costs. Then, we discuss a number of technical issues, which are key to making such integration a reality, and we offer possible approaches to their solution. These issues include efficient frequency and interference management, ...
International police have been deployed on a number of peacekeeping missions, but providing capacity development and assisting in reform of local police in war-torn nations are only a relatively recent undertaking. The process of police reform is complicated because of the inherent difficulty in evaluating the impact of a development programme on police service delivery performance. This study reports on the results of a pilot survey of international police managers assessment of the level of competency of the Royal Solomon Islands Police Force following the introduction of a capacity development programme 3 years earlier. The results indicate that although the local police had improved operationally, and in some cases to an international standard, the Force had lower capability in strateg...
The shift to renewable energy options and low-carbon technologies, in response to the concerns over energy security and climate change, is proceeding more slowly than many would like. The usual argument against rapid deployment of new technologies is the costs imposed on the economy, commonly interpreted in terms of upfront costs to be borne or involving large cash transfers to fund, for example, efforts to preserve rainforests. In this contribution I argue that such a perspective provides a continuing barrier to taking effective action, whereas a perspective based on creation and use of carbon credits provides a means of avoiding the shock of abrupt industrial change. Carbon credits granted for bona fide carbon load reductions could be created through private initiative, for example by me...
A 46.3-ft-dia 20-degree conical ribbon parachute has been designed to retard a 2200-lb payload delivered at speeds up to 800 KCAS and at altitudes as low as 150 feet above ground level. The parachute uses both Kevlar and nylon materials, some of which were developed specifically for this parachute. The canopy design incorporates a patented construction geometry to minimize stress concentrations. A cluster of three 3.8-ft-dia ribbon parachutes is used to deploy the main parachute in the presence of severe aircraft flow field effects and large payload angles of attack. The results of over 30 full-scale flight tests indicate that fundamental limitations imposed by the dynamics of the air masses inside and behind the canopy determine the ultimate performance of a single large parachute when it is used at a release altitude of 150 ft.
This operation plan covers the period of operations from the time major elements of the joint task force are deployed in the forward area until the completion of on-site operations. It was published for planning purposes only, always subject to periodic revision and refinement as more detailed information became available. ENIWETOK-BIKINI Danger Area, as the term is used in this plan, is that area encompassing ENIWETOK and BIKINI ATOLLS and bounded by the meridians 160 deg 35' - 166 deg 16' east longitude, and by the parallels 10 deg 15' - 12 deg 45' north latitude (an area of 150 by 350 miles).
Well over 90 percent of all motorized transportation is fueled by products of petroleum, but the end of such widespread use of oil may be in sight. Among alternative fuels for land transportation, electricity appears to be the most promising, in part because it can be renewably produced and readily transmitted. The inadequacy and high cost of on-board storage of electrical energy present major challenges to widespread deployment of electric traction, and may do so for many years. On-board generation of electrical energy also presents challenges. The third means of powering electric traction is to provide for connection to the electricity grid while in motion. Grid-connected vehicles (GCVs) are an established feature of many cities and of much inter-city transportation, chiefly as electric ...
The LHCb experiment has chosen to use the SAM framework (Service Availability Monitoring Environment from EGEE-II) [1] make extensive tests of the LHCb environment at all the accessible grid resources. The availability and the proper definition of the local Computing and Storage Elements, user interfaces as well as the WLCG software environment are checked. The SAM framework is also used to pre-install the LHCb applications in the shared software area provided by each site. The deployment of the LHCb applications is based on a python tool developed inside the experiment. It is used for software management including incremental installation of interdependent packages and clean package removal. After the application software is installed a validation test of the whole MC chain is run. According to the results of the experiment specific SAM tests, the sites are (re)integrated into the LHCb production system managed by DIRAC [2]. The possibility of automated dynamic ...
High temperature proton conductor (HTPC) oxides are attracting extensive attention as electrolyte materials alternative to oxygen-ion conductors for use in solid oxide fuel cells (SOFCs) operating at intermediate temperatures (400-700 "0C). The need to lower the operating temperature is dictated by cost reduction for SOFC pervasive use. The major stake for the deployment of this technology is the availability of electrodes able to limit polarization losses at the reduced operation temperature. This review aims to comprehensively describe the state-of-the-art anode and cathode materials that have so far been tested with HTPC oxide electrolytes, offering guidelines and possible strategies to speed up the development of protonic SOFCs. (topical review)
On Oct. 24, 2005, Hurricane Wilma, a category 5 storm, made landfall at Cape Romano, Florida. Three days later, the Center for Robot-Assisted Search and Rescue at the University of South Florida deployed an iSENYS helicopter and a prototype unmanned water surface vehicle, AEOS-1, to survey damage in parts of Marco Island, 14 km from landfall. The effort was the first known use of unmanned sea surface vehicles (USVs) for emergency response and established their suitability for the recovery phase of disaster management by detecting damage to seawalls and piers, locating submerged debris (moorings and handrails), and determining safe lanes for sea navigation. It provides a preliminary domain theory of postdisaster port and littoral inspection with unmanned vehicles for use by the human-robot ...
A burner system particularly useful for downhole deployment includes a tubular combustion chamber unit housed within a tubular coolant jacket assembly. The combustion chamber unit includes a monolithic tube of refractory material whose inner surface defines the combustion zone. A metal reinforcing sleeve surrounds and extends the length of the refractory tube. The inner surface of the coolant jacket assembly and outer surface of the combustion chamber unit are dimensioned so that those surfaces are close to one another in standby condition so that the combustion chamber unit has limited freedom to expand with that expansion being stabilized by the coolant jacket assembly so that compression forces in the refractory tube do not exceed about one-half the safe compressive stress of the material; and the materials of the combustion chamber unit are selected to establish thermal gradient parameters across the combustion chamber unit to maintain the refractory tube in ...
Microbonding of the CMS Tracker Inner Barrel (TIB) and Tracker Inner Disks (TID) modules was shared among six different Italian Institutes. The organization devised and the infrastructure deployed to handle this task is illustrated. Microbonding specifications and procedures for the different types of TIB and TID modules are given. The tooling specially designed and developed for these types of modules is described. Experience of production is presented. Attained production rates are given. An analysis of the microbonding quality achieved is presented, based on bond strengths measured in sample bond pull tests as well as on rates of bonding failures. Italian Bonding Centers routinely performed well above minimum specifications and a very low global introduced failure rate, at the strip level, of only $\\sim$0.015 \\% is observed.
A new German-engineered articulated drilling tool that can take the vertical to the horizontal, using about eight metres of curve, was described. The Articulate Downhole Motor has the capability to run radii as long as 57 metres (the usual requirement is 15 metres), under full control. Its ability to rotate and slide while maintaining control is one of the major positives of the technology. The technology also includes a `positive` communication system in its steering tool. The deployment of the positive pulse retrievable measurement-while-drilling (MWD) system brings real-time tool face orientation and hole direction to the surface. In using the tool, formation composition is not an issue; it is designed to withstand any environment.
Department of Foreign Affairs and International Trade services designed to assist businesses to effectively operate in global markets, were described. The goal of the Department is to give strategic targeted information that extends beyond export opportunities to include market access, investment, strategic alliances, technology transfer and competitiveness issues. These services constitute the Department`s Trade Commissioner Service, a network of 600 officers, deployed in 128 embassies and consulates worldwide to support Canadian business development initiatives across 16 sectors of the government`s International Trade Business Plan (ITBP). The Trade Commissioner Service programs include the WIN exporters database, a trade inquiries sourcing team, International Financial Institutions (IFI) projects, and the Program for Export Market Development (PEMD). A series of Sectoral Advisory Groups on International Trade (SAGIT) have been established to facilitate the needs ...
Vehicular communication (VC) systems have recently drawn the attention of industry, authorities, and academia. A consensus on the need to secure VC systems and protect the privacy of their users led to concerted efforts to design security architectures. Interestingly, the results different project contributed thus far bear extensive similarities in terms of objectives and mechanisms. As a result, this appears to be an auspicious time for setting the corner-stone of trustworthy VC systems. Nonetheless, there is a considerable distance to cover till their deployment. This paper ponders on the road ahead. First, it presents a distillation of the state of the art, covering the perceived threat model, security requirements, and basic secure VC system components. Then, it dissects predominant assumptions and design choices and considers alternatives. Under the prism of what is necessary to render secure VC systems practical, and given possible non-technical influences, ...
A variety of forecasting approaches have been used in the energy area. Forecast simulations provide a common basis for comparing the relative precision of different forecasting methods. This paper presents a forecast simulation made using smoothing procedures for forecasting time series. The simulation design, statistical analysis, and conclusions are provided.
The paper sets up a simulation of a geothermal heat pump with a non-azeotropic mixture. The model is modified and verified with experimental data. The results of the simulation show that the systematic model can predict the performance within {+-}12% of the experimental data. As a result, some improvements can be provided on the basis of the simulation platform. (Author)
University research group with research areas: * Land based and submersible autonomous robots, (UUVs: AUVs and ROVs); * Controllers, electronics, sensor design and fusion, motion control; * Guidance and navigation of underwater vehicles; * AI, neural networks, fuzzy logic, subsumption control, behaviour based control; * Optical fibre and ultrasonic sensors for proximal object detection; * Robot arm control, visual servoing; * Imaging sonar applications; * Simulator development: UUV simulator; imaging sonar simulator; Aircraft/flight simulator.
In connection with the ERP project 'Dynamic modelling of staged gasification processes' a gasification simulator has been constructed. The simulator consists of: a mathematical model of the gasification process developed at Technical University of Denmark, a user interface programme, IGSS, and a communication interface between the two programmes. (BA)
2D simulation modeling of a river basin is based on notion of a River Basin as an opened non equilibrium nature system. All components of the system (elevation, water, soil properties and others) are linked to single multi - functional model. The objective of flood simulation is one the model functions. The objectives of the paper are as follows: a mean scale basin floods computing and the model validation; a large scale basin simulation and demands for its validation; results and demands for flood hazard assessment. (orig.)
A three-dimensional numerical simulation of mammatus-like clouds is presented. A portion of a cirrus outflow anvil cloud is simulated including cloud ice and snow microphysical representations. The simulated mammatus clouds appear in a cellular pattern and are compared with the few available previously published physical observations of mammatus. Copyright Copyright 2006 Royal Meteorological Society
The magnicon is a highly attractive candidate to be the RF source for a future multi-Tev linear collider. Physical models and computer codes have been developed which can provide start-to-end self-consistent simulations of a magnicon, including precise simulations of the high-convergence electron gun, RF-system, magnetic system, and beam collector. The 3-D beam dynamics simulations include realistic fields, finite beam size and transverse space charge effects. The codes allow one to provide steady-state simulations of the entire tube, so as to evaluate transient process of magnicon excitation, parasitic mode self-excitation, stability analysis, and tolerance analysis. The results of the simulations are found to be in good agreement with magnicon experiments. A brief description of the physical models and simulation codes employed will be given.
In this paper we present results of using parallel supercomputers to simulate beam dynamics in next-generation high intensity ion linacs. Our approach uses a three-dimensional space charge calculation with six types of boundary conditions. The simulations use a hybrid approach involving transfer maps to treat externally applied fields (including rf cavities) and parallel particle-in-cell techniques to treat the space-charge fields. The large-scale simulation results presented here represent a three order of magnitude improvement in simulation capability, in terms of problem size and speed of execution, compared with typical two-dimensional serial simulations. Specific examples will be presented, including simulation of the spallation neutron source (SNS) linac and the Low Energy Demonstrator Accelerator (LEDA) beam halo experiment.
;Contents: Comparison of Simulation Modules of TRANSYT and INTEGRATION Models; Evaluation of SCATSIM-RTA Adaptive Traffic Network Simulation Model; Comparison NETSIM, NETFLO I, and NETFLO II Traffic Simulation Models for Fixed-Time Signal Control; Traffic Flow Simulation Through Parallel Processing; Cluster Analysis as Tool in Traffic Engineering; Traffic Platoon Dispersion Modeling on Arterial Streets; Hybrid Model for Estimating Permitted Left-Turn Saturations Flow Rate; and Passing Sight Distance and Overtaking Dilemma on Two-Lane Roads.
The full scope simulator in Daya Bay Nuclear Power Station is imported from THOMSON-CSF company in France. It is a large facility, using digital simulation technology, that simulate the main control room of Daya Bay Nuclear Power Station with the high fidelity. It is used for training operators; system analyzing including operation procedure verification. The input output interface system of the simulator is the bridge of the information exchange between instrumentation and the computer. From the point of view of data transfer, this paper discusses the operation principle of the I/O interface system.
This paper describes a simulation model for predicting end-use energy consumption in residential sectors of a city or region. In this model, the annual energy consumption of a dwelling is simulated from the occupants' schedule of living activities, weather data and energy efficiencies of appliances and dwellings. By summing up the simulation results for various household categories, total energy consumption for the residential sector in a region can be estimated. In this paper, energy consumption for Osaka City is simulated. The result is compared with statistical data. The effects of energy efficiency standards and urban heat island phenomena are examined. (author)
The author describes the purpose, classification and main process of acceptance test of full scope simulator of Daya Bay Nuclear Power Plant, including the correction of non-conformance items which are discovered during the performance of acceptance tests. The results of the acceptance tests show that the model accepted by the full scope simulator of Daya Bay Nuclear Power Plant is fully able to cope with the simulation of normal transients and incidental transients and the performance of the simulator indeed compiled with the technical specifications which are defined n the relevant contracts.
Steam generators for nuclear plants require access to the primary and secondary side for various inspection, cleaning and repair procedures and upon achieving access various inspection and cleaning tasks must be carried out. Steam generators currently at manufacture are therefore provided with; primary side access via the primary manways, steam drum access via the steam drum manway, U-bend region access via the secondary manway and drum-internals access passages, tubesheet secondary side access via tubesheet level inspection ports and tube support plate access via tube support level access ports. Many CANDU steam generators were built with only primary and drum manways and either no tubesheet ports or ports which were located ineffectively. The steam generators at Wolsong 1 were built with secondary side inspection ports that provided only limited access away from the no-tube-lane. In addition they have very difficult internal no-tube-lane access. Likewise, Units 2, 3 and 4 were built ...
Concentrating solar power (CSP) technologies continue to mature and are being deployed worldwide. Power towers will likely play an essential role in the future development of CSP due to their potential to provide dispatchable solar electricity at a low cost. This Power Tower Technology Roadmap has been developed by the U.S. Department of Energy (DOE) to describe the current technology, the improvement opportunities that exist for the technology, and the specific activities needed to reach the DOE programmatic target of providing competitively-priced electricity in the intermediate and baseload power markets by 2020. As a first step in developing this roadmap, a Power Tower Roadmap Workshop that included the tower industry, national laboratories, and DOE was held in March 2010. A number of technology improvement opportunities (TIOs) were identified at this workshop and separated into four categories associated with power tower subsystems: solar collector field, ...
Following the Chernobyl nuclear disaster, a considerable amount of effort and resources were allocated worldwide to designing and developing coherent and comprehensive decision support systems for nuclear or radiological emergency management. They range from simple radiological consequence assessment tools to more advanced systems, incorporating the assessment of countermeasures and their effectiveness. Furthermore, many of these systems have been tailored to answer to national emergency preparedness requirements and in some cases such as the R.O.D.O.S. and A.R.G.O.S. systems they have been successfully deployed in a number of countries. Thus, computer based decision support systems for nuclear emergencies are nowadays a reality in Europe, the US and Japan; however, there was a lack of an adequate information and data exchange mechanism that enabled them to function properly and serve the purpose that triggered their development. Within the EURATOM 5. Framework ...
Early in the Cold War, the United States adopted a policy of ''extended nuclear deterrence'' to protect its allies by threatening a nuclear strike against any state that attacks these allies. This threat can (in principle) be used to try to deter an enemy attack using conventional weapons or one using nuclear, chemical, or biological weapons. The credibility of a nuclear threat has long been subject to debate and is dependent on many complex geopolitical factors, not the least of which is the military capabilities of the opposing sides. The ending of the Cold War has led to a significant decrease in the number of strategic nuclear weapons deployed by the United States and Russia. START II, which was recently ratified by the Russian Duma, will (if implemented) reduce the number deployed strategic nuclear weapons on each side to 3500, compared to a level of over 11,000 at the end of the Cold War in 1991. The ...
The Fixed Bed Nuclear Reactor (FBNR) is a small 40 MWe reactor based on the Pressurized Water Reactor (PWR) technology. FBNR is an integrated primary circuit and simple in design. It has the characteristics of being small, modular, proliferation resistant, inherently safe and passively cooled reactor with reduced adverse environmental impact. It utilizes the fuel designed for high temperature reactors operating in a relatively low temperature of PWR environment The 15 mm diameter spherical fuel elements are made of TRISO type microspheres embedded in graphite and cladded by SiC. The coolant flow transfers them from the fuel chamber into the core and become fixed forming a suspended core. Any accident signal will cut off the power to the coolant pump causing a stop in the flow. This results in making the fuel elements fall out of the reactor core by the force of gravity and return into the fuel chamber where they are passively cooled under subcritical condition. Therefore, the ...
The eastern oyster (Crassostrea virginica) developed neoplastic disorders when experimentally exposed both in the laboratory and field to chemically contaminated sediment from Black Rock Harbor (BRH), Bridgeport, Connecticut. Neoplasia was observed in oysters after 30 or 60 days of continuous exposure in a laboratory flow-through system to a 20 mg/L suspension of BRH sediment plus postexposure periods of 3, 30, or 60 days. Composite tumor incidence was 13.6% for both exposures. Tumor occurrence was highest in the renal excretory epithelium, followed in order by gill, gonad, gastrointestinal, heart, and embryonic neural tissue. Regression of experimental neoplasia was not observed when the stimulus was discontinued. In field experiments, gill neoplasms developed in oysters, deployed in cages for 30 days at BRH and 36 days at a BRH dredge material disposal area in Central Long Island Sound, and kidney and gastrointestinal neoplasms developed in caged oysters ...
This paper assesses the effects of including carbon dioxide capture and storage (CCS) damage costs in a long-term energy scenario analysis for Europe. An external cost sensitivity analysis is performed with a bottom-up energy technology model that accounts not only for CCS technologies but also for their external costs. Our main conclusion is that in a business-as-usual scenario (i.e. without climate change intervention or externality internalisation), CCS technologies are likely to be deployed at least to some extent, mainly in the power generation sector, given the economic benefits of opportunities such as enhanced coal bed methane, oil and gas recovery. Under a strict climate (CO{sub 2} emissions) constraint, CCS technologies are deployed massively. With the simultaneous introduction of both CO{sub 2} and CCS taxation in the power sector, designed to internalise the external atmospheric and geological effects of CO{sub 2} emissions and ...
Geological carbon dioxide capture and storage (CCS) is currently seriously considered for addressing, in the near term, the problem of climate change. CCS technology is available today and is expected to become an increasingly affordable CO2 abatement alternative. Whereas the rapidly growing scientific literature on CCS as well as experimental and commercial practice demonstrate the technological and economic feasibility of implementing this clean fossil fuel option on a large scale, relatively little attention has been paid so far to the risks and environmental externalities of geological storage of CO2. This paper assesses the effects of including CCS damage costs in a long-term energy scenario analysis for Europe. An external cost sensitivity analysis is performed with a bottom-up energy technology model that accounts not only for CCS technologies but also for their external costs. Our main conclusion is that in a business-as-usual scenario (i.e. without climate change intervention ...
Developing and deploying innovative environmental cleanup technologies is an important goal for the U.S. Department of Energy (DOE), which faces challenging remediation problems at contaminated sites throughout the United States. Achieving meaningful, constructive stakeholder involvement in cleanup programs, with the aim of ultimate acceptance of remediation decisions, is critical to meeting those challenges. DOE`s Office of Technology Development sponsors research and demonstration of new technologies, including, in the past, the Volatile Organic Compounds Arid Site Integrated Demonstration (VOC-Arid ID), hosted at the Hanford Site in Washington State. The purpose of the VOC-Arid ID has been to develop and demonstrate new technologies for remediating carbon tetrachloride and other VOC contamination in soils and ground water. In October 1994 the VOC-Arid ID became a part of the Contaminant Plume Containment and Remediation Focus Area (Plume Focus Area). The VOC ...
In this paper, numerical simulation of a concentric tube heat exchanger is presented to determine the convective heat transfer coefficient and friction factor in a smooth tube. Increasing the convective heat transfer coefficient can increase heat transfer rate in a concentric tube heat exchanger from a given tubular surface area. This can be achieved by using heat transfer augmentation devices. This work constitutes the initial phase of the numerical simulation of heat transfer from tubes employing augmentation devices, such as twisted tapes, wire-coil inserts, for heat transfer enhancement. A computational fluid dynamics (CFD) simulation tool was developed with CFX software and the results obtained from the simulations are validated with the empirical correlations for a smooth tube heat exchanger. The difficulties associated with the simulation of a heat exchanger augmented with ...
Details of the interaction of photons with tissue phantoms are elucidated using Monte Carlo simulations. In particular, photon sampling volumes and photon pathlengths are determined for a variety of scattering and absorption parameters. The Monte Carlo simulations are specifically designed to model light delivery and collection geometries relevant to clinical applications of optical biopsy techniques. The Monte Carlo simulations assume that light is delivered and collected by two, nearly-adjacent optical fibers and take into account the numerical aperture of the fibers as well as reflectance and refraction at interfaces between different media. To determine the validity of the Monte Carlo simulations for modeling the interactions between the photons and the tissue phantom in these geometries, the simulations were compared to measurements of aqueous suspensions of polystyrene ...
Field-grown snap bean plants were treated with simulated acidic rain applied either alone or in combination with ambient rain and the effects on growth and yield were determined. In plots where ambient rain was excluded, a retractable canopy was activated to shield the crop. Four levels of acidity at pH values of 5.0, 4.2, 3.4 and 2.6 were applied in four replicate treatments and the experiment was conducted in two successive years (1981 and 1982). In plots that received only simulated rain, yield was not adversely affected by acidic rain; in 1981, a positive linear relationship was present between acidity of simulated rain and yield, but in 1981, no effect was found. In contrast, in plots that received both simulated and ambient rain, a negative linear relationship between acidity in simulated rain and yield was observed in both years.
We have carried out numerical simulations of strongly gravitating systems based on the Einstein equations coupled to the relativistic hydrodynamic equations using adaptive mesh refinement (AMR) techniques. AMR coalescences of neutron stars can now be simulated with sufficient resolution covering the neutron stars while having the computational domain extend to the local wave zone. We show an AMR simulation carried out with a workstation having an accuracy equivalent to that of a 1025^3 regular uni-grid simulation, which is, to the best of our knowledge, larger than all previous simulations of similar NS systems on supercomputers. We believe the capability opens new possibilities in general relativistic simulations.
Although computer simulation has played a central role in the study of nucleation and growth since the earliest molecular dynamics simulations almost 50 years ago, confusion surrounding the effect of finite size on such simulations have limited their applicability. Modeling solidification in molten tantalum on the BlueGene/L computer, we report here on the first atomistic simulation of solidification that verifies independence from finite size effects during the entire nucleation and growth process, up to the onset of coarsening. We show that finite size scaling theory explains the observed maximal grain sizes for systems up to about 8,000,000 atoms. For larger simulations, a cross-over from finite size scaling to more physical size-independent behavior is observed.
The traditional process for developing large-scale simulations is cumbersome, time consuming, costly, and in some cases, inadequate. The topics of software components and component-based software engineering are being explored by software professionals in academic and industrial settings. A component is a well-delineated, relatively independent, and replaceable part of a software system that performs a specific function. Many researchers have addressed the potential to derive a component-based approach to simulations in general, and a few have focused on military simulations in particular. In a component-based approach, functional or logical blocks of the simulation entities are represented as coherent collections of components satisfying explicitly defined interface requirements. A simulation is a top-level aggregate comprised of a collection of components that interact with each ...
This paper describes TENT, a system designed for integrating the various tools and parts of a CFD simulation system (CFD - Computational Fluid Dynamics) and the simulation code itself in one interactive simulation environment. Initially the system was intended to be a TEstbed for Numerical Turbine simulation but it turned out that the approach was general enough to be suitable for more complex simulation tasks in the field of aircraft simulation. The paper will give a brief description of a CFD simulation system and its component interactions, which are the basis for describing the Component Architecture based on CORBA. This includes the control architecture using an event model and data flow considerations. Because most CFD codes use parallelization techniques based on Message Passing, a so called MIMD Object Abstraction is described in ...
Many simulation studies in biomedicine are based on a similar sequence of processing steps, starting from images and running through geometric model generation, assignment of tissue properties, numerical...Full Text Available
For the recruitment, training and position qualification of the simulator instructors and feedback of training effect, the management approaches are formulated in 'The System for Simulator Training and Licensing Examination of Daya Bay Nuclear Power Station Operators'. The concrete requirements on the professional knowledge, work experience and foreign language ability of a simulator instructor are put forward. The process of instructor training is designed. The training items include the trainer training, pedagogy training, time management training, operation activities training during outage of unit, 'shadow' training and on-the-jot training on simulator courses. Job rotation is realized between simulator instructor and licensing personnel on site. New simulator instructor must pass the qualification identification. After a duration of 2 years, ...
Solid molecular orthohydrogen exhibits orientational order at low temperatures. The orthohydrogen molecules, which are quadrupoles, order in the Pa3 structure. We have simulated this ordering, and explored the behaviour under dilution by spherical parahydrogen molecules.
We examined the effect of spatial iconicity (a perceptual simulation of canonical locations of objects) and word-order frequency on language processing and episodic memory of orientation. Participants...Full Text Available
This paper reports on Monte Carlo path integral simulations of a Bianchi Type IX cosmology which yield a wave function which reflects the known chaotic dynamics of the classical system and predicts a significant probability for a correlation between large universe volume and large anisotropy.
Combined QM(PM3)/MM molecular dynamics simulations together with QM(DFT)/MM optimizations for key configurations have been performed to elucidate the enzymatic catalysis mechanism on the detoxification...Full Text Available
The percentages of total airflows over the nasal respiratory and olfactory epithelium of female rabbits were calculated from computational fluid dynamics (CFD) simulations of steady-state inhalation....Full Text Available
This paper overviews the general features of computer program 'HEC-5, Simulation of Flood Control and Conservation Systems', with emphasis on the capabilities of the most recent release of HEC-5, Version 7.2, dated March 1991. HEC-5 can simulate the essential features and operation goals and constraints of simple or complex systems with simulation intervals ranging from minutes to one month. Single event flood analysis and period of record conservation analysis may be accomplished with the model. Flood control analysis includes balanced system operation for downstream damage centers with consideration of forecasted local flows and hydrologic routing. In addition, induced surcharge operation based on spillway gate regulation schedules can be simulated. Hydropower analysis may include run-of-river, peaking, and pumped storage plants as well as system power operation. Water supply ...
The effect of feedback and materials on perceptual learning was examined in normal hearing listeners exposed to cochlear implant simulations. Generalization was most robust when feedback paired...Full Text Available
Purpose.The hypothesis that drivers with homonymous hemianopia (HH) would take a lane position that increased the safety margin on their blind side was tested with a driving simulator.Methods.Twelve...Full Text Available
A simulation is developed that qualitatively describes the small-zone-gel-filtration behaviour of a reversibly associating protein. The results reflect the dependence of the apparent molecular weight...Full Text Available
In recent years the modelling of interannual climate variability has been studied, the atmospheric energy and water cycles, and climate simulations with the ECHAM3 model. In addition, the climate simulations of several models have been compared with special emphasis in the area of northern Europe
... program incorporates the proven concepts of advanced distributed learning, modeling and simulation, and electronic digital libraries (Figure 1) to ...
A previous paper introduced the use of wave digital filters as a basic building block for power system simulation, particularly suitable for real-time applications. This paper stresses the simulation of non-linear and switching elements, emphasizing the advantages of the wave filters implementation. The digital structure is maintained even when non-linear components change their characteristics or power electronic devices switch their states. As a very important by-product, the suppression of numerical oscillations related to the trapezoidal rule is achieved in a rather simple way, with no effects on simulation results.
The interaction between a pair of counter-rotating vortices and a lean premixed CH{sub 4}/O{sub 2}/N{sub 2} flame ({Phi} = + 0.55) has been studied by direct numerical simulations using detailed and reduced chemical reaction schemes. Results from the complex chemistry simulation are discussed with respect to earlier experiments and differences in the simulations using detailed and reduces chemistry are investigated. Transient evolutions of the flame surface and the total heat release rate are compared and modifications in the evolution of the local flame structure are displayed. (authors) 22 refs.
This paper describes a signal simulator which is designed to calibrate eddy current probes. By using simultaneously an excitation coil and an electrically conducting plane, the simulator can emulate signals which correspond to spot welds with different flaws. The presence of a conducting plane allows a wide variation of the amplitude and phase of the excitation coil voltage during the calibration of a probe. A mathematical model for the simulator is derived and used to study the variation of the impedance change upon the parameters of the probe. Numerical computation shows that the impedance change depends in an important way on the frequency of the excitation coil current.
... used their Phoenics code to simulate the effect of additives, such as talcum powder which was impregnated in combustible cartridge cases, on the ...
... operation, experimental data reduction, and application of PES results to studies related to estuarine and coastal sediment transport problems are ...
... that defines hydrometeor categories for the duration of the simulation ... and to observe the movement of any particular system ... particle settling occurred ...
12], the Predictive Capability Maturity Model (PCMM) [ref. 13], the Uncertainty Structure scale [ref. 11], and the Simulation Readiness Level (SRL) scale ...
This paper reports that, to obtain better simulation results for a Canada deuterium uranium (CANDU) reactor operation, a new simulation method is developed that uses actual detector readings as a correction factor. Detector readings from a CANDU reactor are used to correct the calculated flux distribution during core calculation iterations. A suitable function is found to describe the relationship between the detector flux and the fluxes of mesh points around the detector. The new simulation method is tested by performing numerical calculations for the Wolsung reactor (a CANDU-600). The results show that the new method predicts the core state more accurately with fewer iterations.
the progressive simplification of composite sandwich panels. The equations ... The thermal and structural behavior of composite sandwich panels with a ...
In this paper we report on multi-physics, multi-billion macroparticle simulation of beam transport in a free electron laser (FEL) linac for future light source applications. The simulation includes a self-consistent calculation of 3D space-charge effects, short-range geometry wakefields, longitudinal coherent synchrotron radiation (CSR) wakefields, and detailed modeling of RF acceleration and focusing. We discuss the need for and the challenges associated with such large-scale simulation. Applications to the study of the microbunching instability in an FEL linac are also presented.
Most of the investigations have a theoretical sustenance based on molecular simulation. The area of application of molecular simulation is very wide, in the Materials Technology Department assigned to the Applied Sciences Management have been treated problems about metallic nano structures, glasses, interfaces, and molecules, to sustain and to explain some of the experimental results. Energy calculations are carried out to determine minimum energy structures, for later on to carry out calculations of some of their properties; as well as the images simulation of Electron microscopy and X-ray diffraction. (Author)
This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users Guide.
This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users' Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users' Guide.
The utilization of electrically heated rods for the simulation of nuclear fuel rods represents an universally adopted method by the nuclear industry to study thermalhydraulic problems. The present work represents the development of a method to obtain the time variation of the electric linear power necessary to simulate a given nuclear power transient in order to yield the same temperature and heat flux conditions in the surface of the electrical heater that would be obtained by the nuclear fuel rod. (Author).
Simulation of the skim-off method for radon measurement by activated charcoal has been carried out by the finite elements method. The variation of radon concentration with peak appearance has been simulated. The thickness of the layer of charcoal removed after exposure and the time of peak appearance have been varied. For the charcoal and canister geometry used, the best results were found when the thickness of the layer removed was 1.72 mm.
2D MEDICI simulator is used to investigate hardening solutions to single-event burnout (SEB). SEB parametric dependencies such as carrier lifetime reduction, base enlargement, and emitter doping decrease have been verified and a p"+ plug modification approach for SEB hardening of power MOSFETs is validated with simulations on actual device structures.
Motivation is given for a technique to more thoroughly test semiconductor equipment control systems. A description is given of a simulator-based control system testing technique. Potential benefits that could be realized by using this technique in the semiconductor industry as well as benefits documented by using this technique in other industries are described. Specific requirements for using the technique in the semiconductor industry are outlined. A summary of a survey of nine commercial simulation systems is given. Finally, the outcome of the survey is compared with the requirements for using the technique.
A phantom simulation imaging quality control device is described that effectively simulates one centimeter lesions, using steel ball bearings as gamma ray attenuators. The bearings are mounted in a synthetic resinous sheet in an orthogonal pattern. The phantom can provide uniformity, resolution, linearity, distortion and field size checks, all with a single exposure.
The upgraded CDF II detector has collected first data during the initial operation of the Tevatron accelerator in Run II. The simulation of the CDF electromagnetic and hadronic central and upgraded plug (forward) calorimeter is based on the Gflash calorimeter parameterization package used within the GEANT based detector simulation of the Run II CDF detector. We present the results of tuning the central and plug calorimeter response to test beam data.
Accurate modeling of system response and scatter distribution is crucial for image reconstruction in emission tomography. Monte Carlo simulations are very well suited to calculate these quantities. However, Monte Carlo simulations are also slow and many simulated counts are needed to provide a sufficiently exact estimate of the detection probabilities. In order to overcome these problems, we propose to split the simulation into two parts, the detection system and the object to be imaged (the patient). A so-called 'virtual boundary' that separates these two parts is introduced. Within the patient, particles are simulated conventionally. Whenever a photon reaches the virtual boundary, its detection probability is calculated analytically by evaluating a multi-dimensional B-spline that depends on the photon position, direction and energy. The unknown B-spline knot values that define ...
The Finnish simulation code APROS and especially its 5-equation model is applied to modelling the horizontal steam generator. Different nodalizations are used in the secondary side of different models. Simulation results of the stationary state run are compared with results of RELAP5/MOD2 calculations and with an experimental plant data. (2 refs., 3 figs., 4 tabs.).
The Finnish simulation code APROS and especially its 5-equation model is applied to modelling the horizontal steam generator. Different nodalizations are used in the secondary side of different models. Simulation results of the stationary state run are compared with results of RELAP5/MOD2 calculations and with an experimental plant data. (2 refs., 3 figs., 4 tabs.).
Both the accuracy and real-time are quite strictly required for the RCS thermal-hydraulic model of the simulation of nuclear power station. So, a large amount of reasonable simplifications should be carried on. The author introduces the RCS thermal-hydraulic model of the full scope simulator of Daya Bay Nuclear Power Station, and emphasizes on the fundamental hypotheses and computation method of its kernel part--DEFI programme.
It is shown that a simple algorithm which exactly segregates between adiabatic and non-adiabatic electrons in particle-in-cell simulations of drift modes yields excellent conservation properties (e.g. particle number, energy) compared to the conventional df scheme. The removal of the free streaming term in the evolution of the marker weight is shown to be responsible for the improved linear and nonlinear properties of the simulated plasma.
This document describes the High Performance Electrical Modeling and Simulation (HPEMS) Global Verification Test Suite (VERTS). The VERTS is a regression test suite used for verification of the electrical circuit simulation codes currently being developed by the HPEMS code development team. This document contains descriptions of the Tier I test cases.
This document describes the High Performance Electrical Modeling and Simulation (HPEMS) Global Verification Test Suite (VERTS). The VERTS is a regression test suite used for verification of the electrical circuit simulation codes currently being developed by the HPEMS code development team. This document contains descriptions of the Tier I test cases.
The SciDAC2 accelerator project at SLAC aims to simulate an entire three-cryomodule radio frequency (RF) unit of the International Linear Collider (ILC) main Linac. Petascale computing resources supported by advances in Applied Mathematics (AM) and Computer Science (CS) and INCITE Program are essential to enable such very large-scale electromagnetic accelerator simulations required by the ILC Global Design Effort. This poster presents the recent advances and achievements in the areas of CS/AM through collaborations.
The mainly nonstationary operation of a solar-heated receiver can be simulated with sufficient accuracy only if data about the dynamic behavior are available. For this reason, the dynamic behavior of a solar cavity receiver with parabolic dish collector is investigated. The development of a mathematical simulation considering heat transfer and storage processes is presented and the procedure for a numerical solution is illustrated. The performance of the calculation method is finally demonstrated by simulating the passage of a cloud.
The mainly instationary operation of a solar heated receiver can be simulated with sufficient accuracy only if data about the dynamic behavior are available. For this reason, the dynamic behavior of a solar cavity receiver with parabolic dish collector is investigated. The development of a mathematical simulation considering heat transfer and storage processes is presented and the procedure for a numerical solution is illustrated. The performance of the calculation method is finally demonstrated by simulating the passage of a cloud.
The characteristics of martensitic transformations in solids are largely determined by the elastic strain that develops as martensite particles grow and interact. To study the development of microstructure, a finite-element computer simulation model was constructed to mimic the transformation process. The transformation is athermal and simulated at each incremental step by transforming the cell which maximizes the decrease in the free energy. To determine the free energy change, the elastic energy developed during martensite growth is calculated from the theory of linear elasticity for elastically homogeneous media, and updated as the transformation proceeds.
This demonstration project uses modern simulation techniques to illustrate the important technologies and design variables that an auto-designer would consider in production a high efficiency, low emissions vehicle. Simulation and modeling techniques use the idea of capturing the relationships between real components of the systems with mathematical equations. These equations are then solved on a computer to simulate the behavior or performance of the system under various conditions. In the current demonstration project, we focus on many variations of a hydrogen-powered vehicle.
A distributed watershed hydrologic model soil and water assessment tool (SWAT, 2000 Version) was applied to simulate stream flow and nutrient loadings (including total nitrogen (TN) and total phosphorus (TP)) in Gucheng Lake Basin, which is located in the lower reach of Yangtze River Basin. Model parameters related to stream flow and nutrient loadings were calibrated and validated by the observed value, and the simulation showed that the simulated values were reasonably comparable to the observed data, suggesting the validity of SWAT model. The simulated surface runoff and nutrient yield between two stages, viz. 1981-2000 and 1951-1960, were compared, basically considering land reclamation in the mid-1970s. The result indicated that, the average annual runoff and output of TN and TP in 198...
During the last years, large-scale simulations of realistic physical environments which support the interaction of multiple participants over the Internet have become increasingly available and economically significant, most notably in the computer gaming industry. Such systems, commonly called networked virtual environments (NVEs), are usually based on a client-server architecture where for performance reasons and bandwidth restrictions, the simulation is partially deferred to the clients. This inevitable architectural choice renders the simulation vulnerable to attacks against the semantic integrity of the simulation: malicious clients may attempt to compromise the physical and logical laws governing the simulation, or to alter the causality of events a posteriori. In this paper, we initiate the systematic study of semantic integrity in NVEs from a security point of view. We argue ...
A compact proton accelerator for medical applications is being developed at Lawrence Livermore National Laboratory. The accelerator architecture is based on the dielectric wall accelerator (DWA) concept. One critical area to consider is the switch region. Electric field simulations and thermal calculations of the switch area were performed to help determine the operating limits of rmed SiC switches. Different geometries were considered for the field simulation including the shape of the thin Indium solder meniscus between the electrodes and SiC. Electric field simulations were also utilized to demonstrate how the field stress could be reduced. Both transient and steady steady-state thermal simulations were analyzed to find the average power capability of the switches.
This project is about the simulation design of an engine control unit (ECU) for an Otto cycle engine with electronic fuel injection (EFI). The simulation includes a model for the ECU as well as physical parameters of the engine, which allows closed-loop control and monitoring of various systems.This simulation has been realized using Simulink and Stateflow, which are components of Mathworks' MATLAB software.The program allows control of various parameters of the ECU, as well as the simulation of failures to verify that the designed ECU is fault-tolerant and can control the engine using an open loop control. The main function the ECU provides is fuel metering.Subsequently, this program could be used as a tool to quickly develop and test models of ECU in order to control an engine in laborat...
We review our recent work on an atomistic approach to the development of predictive process simulation tools. First principles methods, molecular dynamics simulations, and experimental results are used to construct a database of defect and dopant energetics in Si. This is used as input for kinetic Monte Carlo simulations. C and B trapping of the Si self- interstitial is shown to help explain the enormous disparity in its measured diffusivity. Excellent agreement is found between experiments and simulations of transient enhanced diffusion following 20-80 keV B implants into Si, and with those of 50 keV Si implants into complex B-doped structures. Our simulations predict novel behavior of the time evolution of the electrically active B fraction during annealing.
Piping in nuclear power plants is vital to the proper operation and safety of these facilities. To assure safety in the unlikely event of a pipe break, it is necessary to evaluate the consequences from the resulting whipping pipe on neighboring components and structures. Numerical simulations allow for rapid evaluation of these consequences. Before simulations can be accepted, however, the methodology and computer codes must be validated against experimental results. This paper uses a probabilistic approach to validate pipe whip simulations against limited experimental results. Probabilistic analysis software was developed and coupled to existing deterministic finite element software. An example of a whipping pipe impacting against a reinforced concrete slab was simulated. The described pr...
This paper presents a trial of probabilistic simulation for performance assessment of high-level waste (HLW) disposal using the Monte Carlo method. Based on the Reference Case conceptual model in H12, a new integrated simulation system which allowed us to rapidly evaluate the effect of data uncertainty was developed. The doses to hypothetical exposure group were compared with the results of H12 that were performed by using a point-wise approach, in terms of maximum total dose. This study showed that H12 results were consistent with results of probabilistic simulation and also showed that transmissivity had a strong influence for the uncertainty of the system performance in all simulation time. (author)
The UK government's economy-wide 60% carbon dioxide reduction target by 2050 requires a paradigm shift in the whole energy system. Numerous analytical studies have concluded that the power sector is a critical contributor to a low carbon energy system, and electricity generation has dominated the policy discussion on UK decarbonisation scenarios. However, range of technical, social and market challenges, combined with alternate market investment strategies mean that large scale deployment of key classes of low carbon electricity technologies is fraught with uncertainty. The UK MARKAL energy systems model has been used to investigate these long-term uncertainties in key electricity generation options. A range of power sector specific parametric sensitivities have been performed under a 'what-if' framework to provide a systematic exploration of least-cost energy system configurations under a broad, integrated set of input assumptions. In ...
The UK government's economy-wide 60% carbon dioxide reduction target by 2050 requires a paradigm shift in the whole energy system. Numerous analytical studies have concluded that the power sector is a critical contributor to a low carbon energy system, and electricity generation has dominated the policy discussion on UK decarbonisation scenarios. However, range of technical, social and market challenges, combined with alternate market investment strategies mean that large scale deployment of key classes of low carbon electricity technologies is fraught with uncertainty. The UK MARKAL energy systems model has been used to investigate these long-term uncertainties in key electricity generation options. A range of power sector specific parametric sensitivities have been performed under a 'what-if' framework to provide a systematic exploration of least-cost energy system configurations under a broad, integrated set of input assumptions. In this paper results of six ...
The US Department of Energy has provided support to four universities and the Oak Ridge National Laboratory in order to pursue research leading to the development and deployment of an advanced robotic system capable of performing tasks that are hazardous to humans, that generate significant occupational radiation exposure, and/or whose execution times can be reduced if performed by an automated system. The goal is to develop a generation of advanced robotic systems capable of performing surveillance, maintenance, and repair tasks in nuclear facilities and other hazardous environments. This goal will be achieved through a team effort among the Universities of Florida, Michigan, Tennessee, Texas, and the Oak Ridge National Laboratory, and their industrial partners, Combustion Engineering, Martin Marietta Baltimore Aerospace, Odetics, Remotec, and Telerobotics International. Each of the universities and ORNL have ongoing activities and corresponding facilities in ...
subsequent to its in-reactor dwell time, spent fuel still contains large amounts of materials that are recoverable, for value-added energy purposes (uranium, plutonium), together with fission products, and minor actinides, making up the residues from nuclear reactions. The treatment and recycling of spent nuclear fuel, as implemented in France, entail that such materials be chemically partitioned. The development of the process involved, and its deployment on an industrial scale stand as a high achievement of French science, and technology. Treatment and recycling allow both a satisfactory management of nuclear waste to be implemented, and substantial savings, in terms of fissile material. Bolstered of late as it has been, due to spectacularly skyrocketing uranium prices, this strategy is bound to become indispensable, with the advent of the next generation of fast reactors. This Monograph surveys the chemical process used for spent fuel treatment, and its ...
A novel system has been deployed to obtain geochemical samples of water and gas, at in situ pressure, during a geologic CO2 sequestration experiment conducted in the Frio brine aquifer in Liberty County, Texas. Project goals required high-frequency recovery of representative and uncontaminated aliquots of a rapidly changing two-phase (supercritical CO2-brine) fluid from 1.5 km depth. The datasets collected, using both the liquid and gas portions of the downhole samples, provide insights into the coupled hydro-geochemical issues affecting CO2 sequestration in brine-filled formations. While the basic premise underlying the U-Tube sampler is not new, the system is unique because careful consideration was given to the processing of the recovered two-phase fluids. In particular, strain gauges mounted beneath the high-pressure surface sample cylinders measured the ratio of recovered brine to supercritical CO2. A quadrupole mass spectrometer provided real-time gas ...
The Mixed Waste Management Facility, or MWMF, has been proposed as a national testbed facility for the demonstration and evaluation of technologies that are alternatives to incineration for the treatment of mixed low-level waste. The facility design will enable evaluation of technologies at pilot scale, including all aspects of the processes, from receiving and feed preparation to the preparation of final forms for disposal. The MWMF will reduce the risk of deploying such technologies by addressing the following: (1) Engineering development and scale-up. (2) Process integration and activation of the treatment systems. (3) Permitting and stakeholder issues. In light of the severe financial constraints imposed on the DOE and federal programs, DOE/HQ requested a study to assess the cost benefit for the MWMF given other potential alternatives to meet waste treatment needs. The MVVMF Project was asked to consider alternatives specifically associated with ...
Nuclear energy plays an important role in electricity generation, producing 16% of the world's electricity at the beginning of 1999. It has proven to be safe, reliable, economical and has only a minimal impact on the environment. Most of the world's energy consumption, however, is in the form of heat. The market potential for nuclear heat was recognized early. Some of the first reactors were used for heat supply, e.g. Calder Hall (United Kingdom), Obninsk (Russian Federation), and Agesta (Sweden). Now, over 60 reactors are supplying heat for district heating, industrial processes and seawater desalination. But the nuclear option could be better deployed if it would provide a larger share of the heat market. In particular, seawater desalination using nuclear heat is of increasing interest to some IAEA Member States. In consideration of the growing experience being accumulated, the IAEA periodically reviews the progress and new developments in the field of nuclear ...
Rapid growth in economic development, coupled with the absence of an electric grid in large areas of the rural countryside, have created a need for new energy sources both in urban centers and rural areas in China. Environmental pollution from the increased use of coal-fired steam turbines to meet this capacity expansion is a concern. There is a growing interest in China to develop renewable-energy resources and technologies to meet energy demands and help mitigate pollution problems. In February 1995, Secretary Hazel O`Leary of the U.S. Department of Energy signed an Energy Efficiency and Renewable Energy Protocol Agreement with the Chinese State Science and Technology Commission in Beijing, China. Under this agreement, projects using photovoltaics for rural electrification are being conducted in Gansu Province in western China and Inner Mongolia in northern China, providing the basis for much wider deployment and use of photovoltaics for meeting the growing rural ...
ObjectivesThe overall objective is to establish rigorous and verified means of deploying FACTS devices as damping controllers so that stability limits of a congested grid can be expanded, with confidence, toward to the thermal limits. A key to this is to ensure that damping of oscillatory modes of the system are robust to the acknowledged variations of the system.~%~~%~The goals are:~%~~%~a) to apply model order reduction techniques to realistic grid systems and verify modes are adequately expressed,~%~~% [continued...]DescriptionTraditionally, the phenomena of inter-area oscillation between generation groups, e.g. England and Scotland, has been avoided through operating point constraints on tie-lines and acceptance of operation at less than thermal capacity. The need to support long distance trading makes such constraints unacceptable. Stability problems can be solved dynamically, rather than avoided through ...
The UK Energy Research Centre (UKERC) in it's submission to the DTI's 2006 Energy Review reminded us that the 'UK has abundant wind, wave and tidal resources available; its mild climate lends itself to bio-energy production, and solar radiation levels are sufficient to sustain a viable solar industry'. These technologies are at different stages of development but they all draw on basic and applied Science and Engineering. The paper will briefly review the renewable energy technologies and their potential for contributing to a sustainable energy supply. Three research topics will be highlighted that bridge the gap between the physics underpinning the energy conversion, and the engineering aspects of development and deployment; all three are highly relevant to the Government's programme on micro-generation. Two are these are taken from field of thin film photovoltaics (PV), one related to novel device development and the other to a measurement technique for assessing ...
We have already developed three conventional and one periodic permanent (PPM) type 50-MW class klystrons, a smart modulator, and the first HOM-free accelerator structure (Choke-mode type, full-scale high power model). A very stable ceramic high voltage monitor was successfully tested up to 367-kV with a 4.5-#mu#sec pulse. A new C-band SiC type high power rf-load, advancing the power handling capability up to 50-MW is now being designed. It should have excellent mass production characteristics as it uses circularly symmetric TM_0_1_1 chained cavities. The first high power prototype of an rf compressor cavity made of a low thermal expansion material (super Invar) was designed to provide stable operation even with a very high Q of 200-k, it was successfully tested the output rf power up to 135-MW, 0.5-#mu#sec pulse width and 50-pps repetition rate. The C-band linac rf-system will be used for the SASE-FEL (SCSS) production project at SPring-8, but SCSS will also serve to verify the design ...
This proceedings is the compilation of papers presented at the ninth PV Performance and Reliability Workshop held at the Sheraton Denver West Hotel on September 4--6, 1996. This years workshop included presentations from 25 speakers and had over 100 attendees. All of the presentations that were given are included in this proceedings. Topics of the papers included: defining service lifetime and developing models for PV module lifetime; examining and determining failure and degradation mechanisms in PV modules; combining IEEE/IEC/UL testing procedures; AC module performance and reliability testing; inverter reliability/qualification testing; standardization of utility interconnect requirements for PV systems; need activities to separate variables by testing individual components of PV systems (e.g. cells, modules, batteries, inverters,charge controllers) for individual reliability and then test them in actual system configurations; more results reported from field experience on modules, ...
As network bandwidth continues to grow and longer paths are used to exchange large scientific data between storage systems and GRID computation, it has become increasingly obvious that there is a need to deploy a packet drop avoidance mechanism into network transmission protocols. Current end-to-end congestion avoidance mechanisms used in Transmission Control Protocol (TCP) have worked well on low bandwidth delay product networks, but with newer high-bandwidth delay networks they have shown to be inefficient and prone to unstable. This is largely due to increased network bandwidth coupled with changes in internet traffic patterns. These changes come from a variety of new network applications that are being developed to take advantage of the increased network bandwidth. This paper will examine the end-to-end congestion avoidance mechanism and perform a step-by-step analysis of its theory. In addition we will propose an alternative approach developed as part of a new ...
A submerged nuclear power station has been proposed as an alternative power station with a relatively low environmental impact for use by both industrialized and developing countries. The station would be placed 10 m above the seabed at a depth of 30--100 m and a distance of 10--30 km from shore. The submerged nuclear power station would be manufactured and refueled in a central facility, thus gaining the economies of factoryfabrication and the flexibility of short-lead-time deployment. To minimize the size of the submerged hull, horizontal steam generators are proposed for the primary-to-secondary heat transfer, instead of the more traditional vertical steam generators. The horizontal steam generators for SNPS would be similar in design to the horizontal steam generators used in the N-Reactors except the tube orientation is horizontal (the tube's inlet and outlet connection points on the tubesheet are at the same elevation). Previous RELAP5 input decks ...
A submerged nuclear power station has been proposed as an alternative power station with a relatively low environmental impact for use by both industrialized and developing countries. The station would be placed 10 m above the seabed at a depth of 30--100 m and a distance of 10--30 km from shore. The submerged nuclear power station would be manufactured and refueled in a central facility, thus gaining the economies of factoryfabrication and the flexibility of short-lead-time deployment. To minimize the size of the submerged hull, horizontal steam generators are proposed for the primary-to-secondary heat transfer, instead of the more traditional vertical steam generators. The horizontal steam generators for SNPS would be similar in design to the horizontal steam generators used in the N-Reactors except the tube orientation is horizontal (the tube`s inlet and outlet connection points on the tubesheet are at the same elevation). Previous RELAP5 input decks for ...
A submerged nuclear power station has been proposed as an alternative power station with a relatively low environmental impact for use by both industrialized and developing countries. The station would be placed 10 m above the seabed at a depth of 30--100 m and a distance of 10--30 km from shore. The submerged nuclear power station would be manufactured and refueled in a central facility, thus gaining the economies of factoryfabrication and the flexibility of short-lead-time deployment. To minimize the size of the submerged hull, horizontal steam generators are proposed for the primary-to-secondary heat transfer, instead of the more traditional vertical steam generators. The horizontal steam generators for SNPS would be similar in design to the horizontal steam generators used in the N-Reactors except the tube orientation is horizontal (the tube's inlet and outlet connection points on the tubesheet are at the same elevation). Previous RELAP5 input decks for ...
Cellular networks are in a major transition from a carefully planned set of large tower-mounted base-stations (BSs) to an irregular deployment of heterogeneous infrastructure elements that often additionally includes micro, pico, and femtocells, as well as distributed antennas. In this paper, we develop a tractable, flexible, and accurate model for a downlink heterogeneous cellular network (HCN) consisting of K tiers of randomly located BSs, where each tier may differ in terms of average transmit power, supported data rate and BS density. Assuming a mobile user connects to the strongest candidate BS, the resulting Signal-to-Interference-plus-Noise-Ratio (SINR) is greater than 1 when in coverage, Rayleigh fading, we derive an expression for the probability of coverage (equivalently outage) over the entire network under both open and closed access, which assumes a strikingly simple closed-form in the high SINR regime and is accurate down to -4 dB even under weaker ...
In this paper we argue that the set of wireless, mobile devices (e.g., portable telephones, tablet PCs, GPS navigators, media players) commonly used by human users enables the construction of what we term a digital ecosystem, i.e., an ecosystem constructed out of so-called digital organisms (see below), that can foster the development of novel distributed services. In this context, a human user equipped with his/her own mobile devices, can be though of as a digital organism (DO), a subsystem characterized by a set of peculiar features and resources it can offer to the rest of the ecosystem for use from its peer DOs. The internal organization of the DO must address issues of management of its own resources, including power consumption. Inside the DO and among DOs, peer-to-peer interaction mechanisms can be conveniently deployed to favor resource sharing and data dissemination. Throughout this paper, we show that most of the solutions and technologies needed to ...
The Mixed Waste Landfill occupies 2.6 acres in the north-central portion of Technical Area 3 at Sandia National Laboratories, Albuquerque, New Mexico. The landfill accepted low-level radioactive and mixed waste from March 1959 to December 1988. This report represents the Corrective Measures Study that has been conducted for the Mixed Waste Landfill. The purpose of the study was to identify, develop, and evaluate corrective measures alternatives and recommend the corrective measure(s) to be taken at the site. Based upon detailed evaluation and risk assessment using guidance provided by the U.S. Environmental Protection Agency and the New Mexico Environment Department, the U.S. Department of Energy and Sandia National Laboratories recommend that a vegetative soil cover be deployed as the preferred corrective measure for the Mixed Waste Landfill. The cover would be of sufficient thickness to store precipitation, minimize infiltration and deep percolation, support a ...
The Zaafarana oilfield development, operated by Zaafarana Oil Co. (Zafco) presented a series of unique challenges, including redeployment of an internal-turret mooring system, use of a turret-based electrical-cable jumper system, and permanent use of cable-deployed electric submersible pumps in the gravel-pack well completions. Following a detailed three-dimensional (3D) seismic program, the field was discovered by the first well in December 1990. Four subsequent appraisal wells were drilled. The discovery well and two of the appraisal wells tested oil at rates ranging from 2,000 to 10,100 B/D. Initial development plans called for the use of two conventional platforms with a pipeline to a shore-based treatment and storage terminal. Data acquired from subsequent wells were incorporated into the mapping and reserve estimates resulting in a sharp downgrade of the estimated recoverable reserves. The reduced estimate, combined with a revised pricing scenario, ...
A preliminary design effort directed toward a low concentration ratio photovoltaic array system based on 1984 technology and capable of delivering multi-hundred kilowatts (300 kW to 100 kW range) in low Earth orbit is described. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of 0.5 meters x 0.5 meters. Drawings for the preliminary design configuration and for the test hardware that was fabricated for design evaluation and test are provided.
A preliminary design effort directed toward a low concentration ratio photovoltaic array system capable of delivering multihundred kilowatts (300 kW to 1000 kW range) in low earth orbit is described. The array system consists of two or more array modules each capable of delivering between 113 kW to 175 kW using silicon solar cells or gallium arsenide solar cells, respectively. The array module deployed area is 1320 square meters and consists of 4356 pyramidal concentrator elements. The module, when stowed in the Space Shuttle's payload bay, has a stowage volume of a cube with 3.24 meters on a side. The concentrator elements are sized for a geometric concentration ratio (GCR) of six with an aperture area of .25 sq. m. The structural analysis and design trades leading to the baseline design are discussed. It describes the configuration, as well as optical, thermal and electrical performance analyses that support the design and overall performance estimates ...
Nitinol has found growing applications in vascular stents, with the recent introduction on the market of a number of new nitinol tubular devices for coronary and peripheral usage. These stents can be produced either through the expansion of a pattern cut on a small tube (pre-cut) or by cutting the deployed design on a tube of a larger size (pre-expanded). The aim of the study was to analyze the differences of properties induced by the two manufacturing methods. For this purpose, differential scanning calorimetry (DSC) measurements were performed on various specimens from the two types of stents. A first set of measurements shows that pre-expanded stents exhibit usual A<->R<->M transformations whereas multi-stage transformations occur for pre-cut stents. Two types of DSC specimens were then prepared for each stent, corresponding to the straight sections and the curved parts of the stent. It is shown that the pre-cut stents exhibit less ...
In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field ...
The authors report experimental results of heat transfer in the region of transition to turbulence. The augmentation was induced through deployment of periodically placed cylindrical eddy promoters in parallel plane channel flows. Eight different configurations were used. The presence of eddy promoters displaced the point of transition from Reynolds number values of 1500 for the plane channel to around 400 for the least stable case. The value of Nusselt number at the transition for eddy promoters cases was up to 2.5 times higher than the one for the plane channel at the transition. Furthermore, the lower the transition Reynolds number, the higher the Nusselt number at the transition. For the cases where the diameter of the promoters was small and/or the pitch large, the heat transfer results in the transition region were consistent with values obtained from the Reynolds analogy when the analogy was based on the mean transport parameters, i.e., spatially averaged ...
This Phase 1 final report covers the work performed by Springborn Testing and Research, Inc., for the period October 1, 1997 to June 30, 1998 under the Department of Energy Cooperative Agreement Number DE-FC36-97GO10255, entitled Development of Flame Retardant PV Module Encapsulants. While use of roof-mounted arrays has always been an attractive means of deploying PV, only within recent years have such building integrated concepts (BIPV) found renewed interest among module makers and end-users. Prior to building integrated and rooftop applications, flammability requirements for modules have not been a great industry concern. However, with growing interest in BIPV and the requirement for building code requirements for commercial and industrial structures, flammability issues have become a barrier to entry for many module constructions into this potentially huge domestic market for PV. The overall goal of the 3 phase PV BONUS two project is to develop and ...
The SCILS program investigates and demonstrates concepts of operation for dispersed theater forces C3. The dispersal concept would increase the number of potential targets for nuclear strike, make these targets smaller, more highly mobile and harder to find, and introduce functional redundancy. The SCILS system is a microcomputer-based approach to preserving and enhancing the effectiveness of C3 operation in a dispersed configuration. In this program, the system was implemented for testing for the 9th Infantry Division in coordination with the Army's Distributed Command and Control System. Technical highlights of the system include a distributed, replicated data base, a video map/graphics-oriented Commander's Decision Display System, a packet switched Multi-Media Network that operates with deployed field communication systems, and a Voice/Data Conferencing System that supports remote coordination/briefing in a dispersed configuration. The program ...
Automobile has become the dominant transport mode in the world in the last century. In order to meet a continuously growing demand for transport, one solution is to change the control approach for vehicle to full driving automation, which removes the driver from the control loop to improve efficiency and reduce accidents. Recent work shows that there are several realistic paths towards this deployment : driving assistance on passenger cars, automated commercial vehicles on dedicated infrastructures, and new forms of urban transport (car-sharing and cybercars). Cybercars have already been put into operation in Europe, and it seems that this approach could lead the way towards full automation on most urban, and later interurban infrastructures. The European project CyberCars has brought many improvements in the technology needed to operate cybercars over the last three years. A new, larger European project is now being prepared to carry this work further in order to ...
Human resource competence building and continued enhancement of performance is the most vital input for safe and reliable operations of a Nuclear Power Plant. Integrated planning leading to the decision of timely selection of optimum number of fresh people and deployment of experienced manpower with desired lead time is inevitable to achieve the above objective. For safe and reliable plant operation human performance analysis followed by suggestive measures to improve the same is needed. Corrective or strengthening input may be in terms of training, work environment, motivations, organizational culture and climate, leadership and prevailing environmental force and bio-rhythm of individuals with critical days are to be worked out The adequacy in training and development not only gives safe and reliable plant operations but results in greater employee satisfaction and self esteem as well. As of date, in the present vibrant global scenario, only the organization which ...
An important issue towards a broader acceptance of answer-set programming (ASP) is the deployment of tools which support the programmer during the coding phase. In particular, methods for debugging an answer-set program are recognised as a crucial step in this regard. Initial work on debugging in ASP mainly focused on propositional programs, yet practical debuggers need to handle programs with variables as well. In this paper, we discuss a debugging technique that is directly geared towards non-ground programs. Following previous work, we address the central debugging question why some interpretation is not an answer set. The explanations provided by our method are computed by means of a meta-programming technique, using a uniform encoding of a debugging request in terms of ASP itself. Our method also permits programs containing comparison predicates and integer arithmetics, thus covering a relevant language class commonly supported by all state-of-the-art ASP ...
Light duty vehicles, i.e. passenger cars and light trucks, account for approximately half of global transportation energy demand and, thus, a major share of carbon dioxide and other emissions from the transport sector. Energy consumption in the transport sector is expected to grow in the future, especially in developing countries. Cars with alternative powertrains to internal combustion engines (notably battery, hybrid and fuel-cell powertrains), in combination with potentially low carbon electricity or alternative fuels (notably hydrogen and methanol), can reduce energy demand by at least 50%, and carbon dioxide and regulated emissions much further. This article presents a comparative technical and economic assessment of promising future fuel/vehicle combinations. There are several promising technologies but no obvious winners. However, the electric drivetrain is a common denominator in the alternative powertrains and continued cost reductions are important for widespread ...
Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. Reported here are the results of tests of a newly designed boron-lined proportional counter option. This testing measured ...
Citizens Gas and Coke Utility operates three coke oven batteries, producing both foundry coke and blast furnace coke, under the trade name Indianapolis Coke. Active participation in the regulation negotiation process by the Vice President of Indianapolis Coke allowed the company to accurately anticipate the environmental regulations, long before they were set in law. Several improvements were put into motion that helps them meet the new environmental regulations. Better trained operators with new job positions dedicated solely to environmental compliance, an extensive environmental training program, and two innovations, a portable oven door milling and cleaning machine and three new computer applications are the result of team efforts. The focus of this paper is development of the computer applications designed to enhance three areas of environmental compliance. The three areas addressed by the applications are documentation and information deployment, problem ...
Objective: To evaluate the clinical efficacy of multiple stents placement in the management of hilar cholangiocarcinoma, especially in the complex cases of which the hepatic ducts are invaded. Methods: Forty-five consecutive patients with hilar cholangiocarcinoma were treated with percutaneous transhepatic placement of two or three self-expandable metallic endoprostheses. The cause of hilar obstructions in these patients were all cholangiocarcinoma, including Bismuth classification type II (n 12), IIIa (n 17), IIIb (n 10), and IV (n 6). Two or 3 stents were placed in the configuration of T, Y or X over the strictures. Results: Stent placement with 2 or 3 endoprostheses was successful in all patients. All patients showed significant decrease in serum bilirubin level. The mortality rate within 30 days of stent placement was 2.2% (1/45). The mean survival and stent patency times were 215.3 d (26- 516 d) and 181.5 d (26-473 d), respectively. Conclusion: Deploying of ...
Design of energy efficient schemes for data gathering is an important concern for lifetime enhancement of wireless sensor networks. Variation in the distances of nodes from the Base Station and differences in inter-nodal distances are primary factors causing unequal energy dissipation among the nodes. Thus energy difference between the various nodes increases with time resulting in degraded network performance. The LEACH and PEGASIS schemes which provided elegant solutions to the problem suffer basic drawbacks due to randomization of cluster heads and greedy chain formation respectively. In this paper, we propose an Optimized Lifetime Enhancement (OLE) Scheme which shows enhanced performance over these schemes. OLE increases the network performance by ensuring a sub-optimal energy dissipation of the individual nodes despite their random deployment. It employs modern heuristics like particle swarm optimization instead of the greedy algorithm as in PEGASIS to ...
Korea has participated in GIF from early stage, and played an important role in GIF as an original signatory of the GIF Charter. Korea has dispatched two representatives of GIF Policy Group and Expert Group respectively. Korea submitted 10 concepts of Gen IV for Gen IV technology roadmap. Korea's KALIMER and SMART concepts have stood higher in technological evaluation. 7 Korean experts were dispatched for Gen IV technology roadmap (4 from institution, 3 from industry and 1 form academia). Furthermore, USA's NTD (Near term Deployment) will be expanded to I-NTD (International NTD). This study suggested that Korea should propose APR-1400 as I-NTD concept for I-NTD discussion in GIF. Finally, Korea and USA jointly decided to fund 2 million dollars respectively for 2001 I-ERI program and selected 6 projects for the program, which are composed of 4 for LWR area and 2 for I and C area. 27 refs., 6 figs., 11 tabs. (Author)
The popularity of UAVs has increased dramatically because of their successful deployment in military operations, their ability to preserve human life, and the continual improvements in wireless communication that serves to increase their capabilities. We believe the usefulness of UAVs would be dramatically increased if formation flight were added to the list of capabilities. Currently, sustained formation flight with a cluster of UAVs has only been achieved with two nodes by the Multi-UAV Testbed at the Massachusetts Institute of Technology. (Park, 2004) Formation flight is a complex operation requiring the ability to adjust the flight patterns on the fly and correct for wind gusts, terrain, and differences in node equipment. All of which increases the amount of inner node communication. Since one of the problems with MANET communication is network congestion, we believe a first step towards formation flight can be made through improved inner node communication. We ...
A reactor-neutrino experiment, Daya Bay, has been proposed to determine the least-known neutrino mixing angle theta_13 using electron antineutrinos produced at the Daya Bay nuclear power complex in China. Daya Bay is an international collaboration with institutions from China, the United States, the Czech Republic, Hong Kong, Russia, and Taiwan. The experiment will use eight identical detectors deployed at three different locations optimized for monitoring the antineutrino rates from the six reactors and for detecting any rate deficit and spectral distortion near the first oscillation maximum. The overburden of the under ground experimental halls, connected with tunnels, ranges from about 250 to 900 meters-water-equivalent so that the cosmogenic background is small compared to the number of observed antineutrino events. Civil construction of tunnels and experimental facilities is planned to start in 2007, with detector construction beginning in 2008. The experiment ...
The Convective and Orographically-induced Precipitation Study (COPS) has the aim to advance the quality of forecasts of orographically-induced precipitation in complex terrain. COPS is a Research and Development Project of the World Weather Research Program and considered to be one of the largest field campaigns on quantitative precipitation forecasting that has been performed so far. A network of state-of-the-art active and passive remote sensing systems was combined with in total 10 airborne platforms, Meteosat rapid scans and dense networks of standard meteorological instruments during the three months long field phase (June-August, 2007) in south-western Germany/eastern France to observe atmospheric variables in the three spatial dimensions and in time. By the University of Hohenheim, two novel ground-based mobile scanning lidar systems were deployed: a scanning rotational Raman lidar which provides combined measurements of the field of atmospheric temperature ...
The software package VIBA-lab1, which incorporates PIXE and RBS energy spectra simulation has now been extended to include the simulation of elemental maps from 3D structures. VIBA-lab1 allows the user to define a wide variety of experimental parameters, e.g. energy and species of incident ions, excitation and detection geometry, etc. When the relevant experimental parameters as well as target composition are defined, the program can then simulate the corresponding PIXE and RBS spectra. VIBA-LAB2 has been written with applications in nuclear microscopy in mind. A set of drag-and-drop tools has been incorporated to allow the user to define a three-dimensional sample object of mixed elemental composition. PIXE energy spectra simulations are then carried out on pixel-by-pixel basis and the corresponding intensity distributions or elemental maps can be computed. Several simulated ...
The influence of the velocity profile at the inlet boundary on the simulation of air velocity distribution inside an electrostatic precipitator is presented in this study. Measurements and simulations were performed in a duct and an electrostatic precipitator (ESP). A four-hole cobra probe was used for the measurement of velocity distribution. The flow simulation was performed by using the computational fluid dynamics (CFD) code FLUENT. Numerical calculations for the air flow were carried out by solving the Reynolds-averaged Navier-Stokes equations coupled with the realizable k-{epsilon} turbulence model equations. Simulations were performed with two different velocity profiles at the inlet boundary - one with a uniform (ideal) velocity profile and the other with a non-uniform (real) velocity profile to demonstrate the effect of velocity inlet boundary condition on the flow ...
Maps of wind resources were used to develop a method of evaluating climatic changes and their potential impacts on wind energy resources. Global IPCC climate change scenarios were used to predict climatic conditions for the future, while past wind resource availability was simulated and validated using NCEP and NCAR reanalysis data as well as observed meteorological data from Environment Canada. The simulations were used to compare each 5-year period with a 50-year reference period. Regional scale climate change impacts were evaluated using a statistical dynamic down-scaling method. Advanced meteorological models were used to predict wind flow patterns across specific landscapes. The evolution of past wind resource availability was then simulated. Five-year wind resource simulations for a 50-year period were simulated at 25 km"2 wind speeds at 80 m above the ground. Average wind ...
We examine the observable properties of simulated barred galaxies including radial mass profiles, edge-on structure and kinematics, bar lengths and pattern speed evolution for detailed comparison to real systems. We have run several simulations in which bars are created through inherent instabilities in self-consistent simulations of a realistic disc+halo galaxy model with a disc-dominated, flat rotation curve. These simulations were run at high (N=20M particles) and low (N=500K) resolution to test numerical convergence. We determine the pattern speeds in simulations directly from the phase angle of the bar versus time and the Tremaine-Weinberg method. Fundamental dynamics do not change between the high and low resolution, suggesting that convergence has been reached in this case. We find the higher resolution is needed to simulate structural and kinematic ...
Piping in nuclear power plants is vital to the proper operation and safety of these facilities. To assure safety in the unlikely event of a pipe break, it is necessary to evaluate the consequences from the resulting whipping pipe on neighboring components and structures. Numerical simulations allow for rapid evaluation of these consequences. Before simulations can be accepted, however, the methodology and computer codes must be validated against experimental results. This paper uses a probabilistic approach to validate pipe whip simulations against limited experimental results. Probabilistic analysis software was developed and coupled to existing deterministic finite element software. An example of a whipping pipe impacting against a reinforced concrete slab was simulated. The described probabilistic approach was used to validate the numerical simulations. The conclusions obtained ...
A nuclear power plant engineering (NPP) simulator may include many system functions such as thermal-hydraulic calculation, 3D reactor neutron kinetics model, control and protection system, display and operational human-machine interface, intelligent alarm system, etc. If all those functions are simulated using a single code, the size of the program will cause structural or managerial problems, and the hardware requirement could be tremendous. Thus, any local function errors or changes may affect the whole code, which will make development and maintenance extremely costly. So the nondistributed code is not considered to be flexible and feasible. Currently, distributed and parallel technologies have been applied to develop NPPs engineering simulator for safety analysis, verification of advanced main control room display, operation and intelligent alarm design. The distributed simulation divides a huge ...
The plasma plume generated by a new type of high energy Janitor known as the railplug, is examined. The railplug is a miniaturized railgun that has the potential for improving ignition characteristics of combustible mixtures in engines. The objective of the study is to gain an uderstanding of the characteristics of the plasma created by a transparent railplug, and to validate a multidimensional computer simulation of the plasma and shock fronts. The nature of the plume emitted by the railplug was examined for three levels of electrical energy while firing into air at a pressure of 1 atm. The computer model is to be used to predict trends in railplug performance for various railplug designs, energies, and ambient conditions. The velocity of the plasma movement inside a transparent railplug was measured, as well as the velocity of the plume ejected from the cavity. A shock is produced at the initiation point of the arc and propagates down the cavity, eventually ...
The evolution of FRI jets has been long studied in the framework of the FRI-FRII dichotomy. In this paper, we test the present theoretical and observational models via a relativistic numerical simulation of the jets in the radio galaxy 3C 31. We use the parameters derived from the modelling presented by \\cite{lb02a,lb02b} as input parameters for the simulation of the evolution of the source, thus assuming that they have not varied over the lifetime of the source. We simulate about 10 % of the total lifetime of the jets in 3C 31. Realistic density and pressure gradients for the atmosphere are used. The simulation includes an equation of state for a two-component relativistic gas that allows a separate treatment of leptonic and baryonic matter. We compare our results with the modelling of the observational data of the source. Our results show that the bow shock evolves self-similarly at a quasi-constant ...
Ion implantation and subsequent annealing are essential stages in today's advanced CMOS processing. Although the dopant implanted profile can be accurately predicted by analytical fits calibrated with SIMS profiles, the damage has to be estimated with a binary collision approximation implant simulator. Some models have been proposed, like the '+n', in an attempt to simplify the anneal simulation. We have used the atomistic kinetic Monte Carlo dados to elucidate which are the implant modeling features most relevant in the simulation of transient enhanced diffusion (TED). For the experimental conditions studied we find that the spatial correlation of the I, V Frenkel pairs is not critical in order to yield the correct I supersaturation, that can be simulated just taking into account the net I-V excess distribution. In contrast to, simulate impurity clustering/deactivation when there ...
We present a dynamical spectral model for Large Eddy Simulation of the incompressible magnetohydrodynamic (MHD) equations based on the Eddy Damped Quasi Normal Markovian approximation. This model extends classical spectral Large Eddy Simulations for the Navier-Stokes equations to incorporate general (non Kolmogorovian) spectra as well as eddy noise. We derive the model for MHD and show that introducing a new eddy-damping time for the dynamics of spectral tensors in the absence of equipartition between the velocity and magnetic fields leads to better agreement with direct numerical simulations, an important point for dynamo computations.
Energy deposition process by relativistic fast electrons produced by ultra-intense laser pulses is discussed. The process is calculated with a two dimensional Fokker-Planck simulation code including binary and collective collisions coupled with electromagnetic field. We focused on Velocity Distribution Function (VDF) dependence in the simulation. The results show that the spread angle of the fast electrons distribution affects energy deposition area and deposited energy is concentrated in the vicinity of the propagation axis of the fast electrons. It may be also suggested that self-pinch effect of a fast electron beam causes large deposition energy. (author)
The statistical {gamma}-spectra of highly excited even-even rare earth nuclei are simulated applying appropriate level density and strength function to a given nucleus. Hindrance effects due to K-conservation are taken into account. Simulations are compared to experimental data from the {sup 163}Dy({sup 3}He,{alpha}){sup 162}Dy and {sup 173}Yb({sup 3}He,{alpha}){sup 172}Yb reactions. The influence of the K quantum number at higher energies is discussed. 21 refs., 7 figs., 2 tabs.
We investigate the formation of nanostructures in 2D strained alloys on face centered cubic (111) surfaces by means of equilibrium Monte Carlo simulations. In the framework of an off-lattice model, we consider one monolayer of two bulk-immiscible adsorbates A and B with negative and positive misfit relative to the substrate, respectively. Simulations show that the adsorbates partly self-organize into island or stripe-like patterns. We show how these structures depend on the relative misfits, interaction, and concentration of components. The morphology is quite different for phase separation and intermixing regimes.
Numerical simulation of dynamic fracture of concrete slabs, impacted by steel projectiles, was carried out in this study. The concrete response was described by a continuum damage model. This continuum damage model was originally developed to study rock fragmentation and was modified in the present study with an emphasis on the post-limit structural response. The model was implemented into a transient dynamic explicit finite element code LS-DYNA2D and the code was then used for the numerical simulations. The specific impact configuration of this study follows the experiment series conducted by Hanchak et al. Comparisons between calculated results and measured data were made. Good agreements were found.
Tests for the applicability of a CFD (Computational Fluid Dynamics) code for simulating activity transport in PNA (Pulsed Neutron Activation) fluid measurements have been performed. The CFD code was combined with a Monte Carlo code used for the calculation of the initial activity distribution. The results from the calculations show that it is possible to use CFD for calculation of the activity distribution in PNA. The mainly qualitative results in this work are encouraging and suggest further work. In the continuation of this work a response function for the gamma detector will be calculated so that a PNA time spectrum can be simulated. A more accurate comparison with experimental data can then be performed
This report provides test results on the thermal performance of an Owens-Illinois Sunpak liquid, evacuated tube, solar collector under simulated conditions. The test was conducted using the Marshall Space Flight Center Solar Simulator in accordance with the test requirements specified in ASHRAE 93-77 (Method of Testing to Determine the Thermal Performance of Solar Collectors) and the procedures contained in MTCP-FA-SHAC-400 (Procedure for Operation of the MSFC Solar Simulator Facility). The tests were performed on a module used on the early demonstration projects. A current production module is undergoing tests with results to be in a subsequent report.
This revised edition discusses a large number of renewable energy systems. Future trends are outlined. Economic efficiency calculations are explained and analyzed. Many exemplary calculations and graphical representations illustrate the various technologies and methods of calculation. This standard book addresses university students, scientists and engineers in research and industry. The accompanying DVD is one of the most extensive compilations of demo programs and full versions for simulation of renewable energy systems, all illustrations of the book in electronic format, additional text and a user-friendly navigation aid. (orig.)
The present paper is concerned with the prediction method for the motions and tensions of mooring lines on slack-moored floating oceanic architectural building in coastal zone. The motions and the tensions of mooring lines were estimated by the time domain numerical simulation in the present method. The present method includes the nonlinearity of mooring system, slow varying wave drift force. The authors performed a time domain numerical simulation for motions and the tensions of mooring lines on floating barge in two component waves. Also, the results obtained by numerical simulation were compared with the experimental results. The validity of the present method was confirmed.
The validation of the forecast model for early emergency response to nuclear accidents is evaluated by trace tests in atmosphere in Daya Bay nuclear power site. The simulation experiment of the Daya Bay nuclear power site shows that the particle spreading image and the time-integrated concentration distribution given by plume concentration prediction model can perform the variation of pathway of the pollutant transport, as well as the effects of topography on transport and diffusion of pollutants. The simulation of five trace tests in field shows that 59.1% of ratios between predicted results and observed results are within the range of 10, and 41% of ratios are within the range of 5 approximately. (authors)
Three-dimensional magnetohydrodynamic simulations are executed in a full toroidal geometry to clarify the physical mechanisms of the Internal Reconnection Event (IRE), which is observed in the spherical tokamak experiments. The simulation results reproduce several main properties of IRE. Comparison between the numerical results and experimental observation indicates fairly good agreements regarding nonlinear behavior, such as appearance of localized helical distortion, appearance of characteristic conical shape in the pressure profile during thermal quench, and subsequent appearance of the m=2/n=1 type helical distortion of the torus. (author)
A new scheme to accurately retain kinetic electron effects in particle-in-cell (PIC) simulations for the case of electrostatic drift waves is presented. The splitting scheme, which is based on exact separation between adiabatic and on adiabatic electron responses, is shown to yield more accurate linear growth rates than the standard df scheme. The linear and nonlinear elliptic problems that arise in the splitting scheme are solved using a multi-grid solver. The multi-grid particle-in-cell approach offers an attractive path, both from the physics and numerical points of view, to simulate kinetic electron dynamics in global toroidal plasmas.
The solvation properties of a chlorine ion in small water clusters are investigated using state-of-the-art statistical mechanics. The simulations employ the polarizable water model developed recently by Dang [J. Chem. Phys. [bold 97], 2659 (1992)]. The ion--water interaction potentials are defined such that the successive binding energies for the ionic clusters, and the solvation enthalpy, bulk vertical binding energy, and structural properties of the aqueous solution agree with the best available results obtained from experiments. Simulated vertical electron binding energies of the ionic clusters Cl[sup [minus
An accelerator experiment was performed using a low-energy antiproton beam to measure antiproton detection efficiency of BESS, a balloon-borne spectrometer with a superconducting solenoid. Measured efficiencies showed good agreement with calculated ones derived from the BESS Monte Carlo simulation based on GEANT/GHEISHA. With detailed verification of the BESS simulation, the relative systematic error of detection efficiency derived from the BESS simulation has been determined to be {+-}5%, compared with the previous estimation of {+-}15% which was the dominant uncertainty for measurements of cosmic-ray antiproton flux.
In the framework of the carbon storage two forestry methods are analyzed by the author: the standing capitalization (slowing of the crops) and the spices substitution (slow growing species by fast growing species). The construction of a model taking into account the all stage of the carbon implication (biomass, soil, forest products) offers simulation and quantitative results on these methods. (A.L.B.)
The paper is concerned with the simulation of practical testing situations which are too difficult and/or expensive to replicate in a laboratory environment. Numerical experiments are described which simulate the differential eddy current probe response to the build-up and chemical flushing of magnetite in the crevice gap of a PWR steam generator unit. The simulation results agree well with the only experimental data available to the authors and lead to the conclusion that conventional differential eddy current probes should be capable of characterizing crevice gap conditions with respect to the presence of magnetite. (author).
The hot uniform aluminium plasma was produced by irradiating thin aluminium dotted foil smoothly with the 9th 0.53 ?m laser on Shenguang II laser facility. The emitted spectrum was measured from the front and tangential direction of the target with two crystal spectrometers, and the quantitative spectrum from the front of the target was obtained. The state of laser- produced plasma was simulated with the radiation hydrodynamics code MULTI-1D, and the emitted spectrum was calculated with the spectrum code of Collision-Radiation model under the simulated plasma state. The experimental spectrum accords with the simulated one. (authors)
Thermal expansions of a simulated fuel (SS-1) were measured by using a Dilatometer (DIL402C) from room temperature to 1900 K. The main procedure of an uncertainty evaluation followed the strategy of the UO{sub 2} fuel. Referring to the ISO (International Organization for Standardization) guide, the uncertainties of the thermal expansion were quantified in three parts - the initial length, the length variation, and the system calibration factor. The uncertainty of the thermal expansion for a simulated fuel was also compared with those of UO{sub 2} fuel.
The results of this study show that Monte Carlo simulations of diffusion in homogeneous turbulence can be formulated in terms of the Eulerian space-time velocity autocorrelation function. Numerical results obtained using this approach agree with results obtained by Taylor (1921) using the Lagrangian autocorrelation function. Use was made of the equivalence of the Lagrangian and Eulerian Monte Carlo approaches to derive analytic relations between the Lagrangian integral time scale and the Eulerian integral space and time scales. These analytic results were verified by comparison to Monte Carlo simulations and to other theoretical results. They are in general agreement with many existing theories and semi-empirical relations.
It has been issued that ROP(Regional Overpower Protection) for Wolsong Unit 1 needed to be reanalyzed due to the aging effect. Thermo-hydraulics and core simulation have to be performed for calculation of the fuel bundle power, channel power and detector signal production. PPV/MULTICELL/RFSP code system was used to calculate the power distribution for the ROP analysis. In this study, 232 cases out of 926 scenarios which include postulated accidents such as Startup after Short Shutdown, Shim Cases, Stepback, Insertion and Withdrawal of Reactivity Control Rods were simulated.
The simulation of processes in engineering and the physical sciences has progressed rapidly over the last several years. With rapid developments in supercomputers, parallel processing, numerical algorithms and software, scientists and engineers are now positioned to quantitatively simulate systems requiring many billions of arithmetic operations. The need to understand and assimilate such massive amounts of data has been a driving force in the development of both hardware and software to create visual representations of the underling physical systems. In this paper, and the accompanying videotape, the evolution and development of the visualization process in scientific computing will be reviewed. Specific applications and associated imaging hardware and software technology illustrate both the computational needs and the evolving trends. 6 refs.
An accelerator beam experiment was performed using a low-energy antiproton beam to measure antiproton detection efficiency of the BESS detector. Measured and calculated efficiencies derived from the BESS Monte Carlo simulation based on GRANT/GHEISHA showed good agreement. With detailed verification of the BESS simulation, the relative systematic error of detection efficiency derived from the BESS simulation has been determined to be {+-}5%, compared with the previous estimation of {+-}15% which was the dominant uncertainty for measurements of cosmic-ray antiproton flux. (author)
Electrostatic plasma simulation code for 2D rectangular geometry is presented. Main distinguishing feature of the code is its orientation on the beam-plasma interaction. The code and its graphical interface were developed using MATLAB programming language. Simulation results of inhomogeneous plasma interaction with modulated electron beams of different width are compared. In case of wide beam the front of Langmuir waves generated in point of local plasma resonance is planar and in case of thin beam (or ribbon beam) the front has approximately half-circular form.
Engine flow simulation was provided by four separately mounted air ejectors connected to a high-pressure air supply. The engine nacelle center lines were ...
A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wind-turbine rotor. A first-order convection scheme is used which accounts for the decrease in streamwise velocity as the flow passes through the wind-turbine rotor. The VSTOC simulation is independent of the particular analytical technique used to predict the aerodynamic and performance characteristics of the turbine. The VSTOC subroutine may be used simply as a subroutine in a particular VAWT prediction code or it may be used as a subroutine in an independent processor. The independent processor is used to interact with a version of the VAWT prediction code which is segmented into deterministic and stochastic modules. Using VSTOC in this fashion is very efficient with ...
Description of the current status of the developments of a simulation of the Darlington Nuclear Generating Station shutdown and regulating systems, DARSIM. The DARSIM program simulates the spatial neutron dynamics, the regulations of the reactor power, and shutdown system 1 and shutdown system 2 software. The DARSIM program operates in the interactive simulation (INSIM) program environment. DARSIM was installed on the APOLLO computer at the Atomic Energy Control Board (AECB) and a version for an IBM-PC was also provided for the exclusive use of the AECB. Shutdown system software was updated to incorporate the latest revisions in the functional specifications. Additional developments were provided to assist in the use and interpretation of the DARSIM results.
... UGV), in the air (UAV), or underwater (UUV) -across ... Figure 2 Tactical Mobile Robot MOUT concept: ... 10 robots to clear 20 rooms in 60 minutes ...
A catalytic converter of a ceramic monolith honeycomb substrate, coated with a washcoat of catalyst and attached to a natural gas/diesel dual fuel engine was simulated and studied experimentally. The paper describes the application of one-dimensional finite element model for the transient and steady state operation. Laminar flow was approximated using a dispersed plug flow model, and chemical kinetics were simulated using LHHW (Langmuir/ Hinshelwood/ Hougan/ Watson) type expressions. Simulation results were compared with experimental results for heating and cooling cycles which resulted from speed and load changes on the engine. The comparison showed a maximum difference between the two sets of emission levels of about 10 per cent, showing that the one-dimensional model is acceptable model for this dual fuel engine converter combination. 50 refs., 3 tabs., 13 figs.
The antimicrobial activity of simulated solar disinfection (SODIS) in the presence and absence of riboflavin against various protozoa and helminth organisms was investigated in this study. Assays were conducted in transparent 12 well microtitre plates containing a suspension of test organisms in the presence or absence of 250mM riboflavin. Plates were exposed to simulated sunlight at an optical irradiance of 550Wm^-^2 (watts per square metre) delivered from a SUNTEST(TM) CPS+ solar simulator. Aliquots of the test suspensions were taken at set time points and the viability of the test organisms was determined by either culture, microscopy or flow cytometry where applicable. With Acanthamoeba, Naegleria, Entamoeba and Giardia exposure to SODIS at an optical irradiance of 550Wm^-^2 for up to ...
Inductive electromagnetic launchers, or coilguns, use discrete solenoidal coils to accelerate a coaxial conductive armature. To date, Sandia has been using an internally developed code, SLINGSHOT, as a point-mass lumped circuit element simulation tool for modeling coilgun behavior for design and verification purposes. This code has shortcomings in terms of accurately modeling gun performance under stressful electromagnetic propulsion environments. To correct for these limitations, it was decided to attempt to closely couple two Sandia simulation codes, Xyce and ALEGRA, to develop a more rigorous simulation capability for demanding launch applications. This report summarizes the modifications made to each respective code and the path forward to completing interfacing between them.
Abstract Suspension of solids in stirred reactor is widely used for catalytic reactions, dissolution, etc. Quality of solid suspension is an important parameter required for the reliable design, optimum performance, and scale up of the system. Quality of suspension depends on local characteristics of solid velocity and hold up profiles. The present work was focused on investigating quality of solid suspension using ultrasound velocity profiler (UVP) measurements and CFD simulations. The slip velocity measurements carried out with UVP were used to evaluate different drag correlations used in CFD simulations. Results discussed in this work would be useful for extending the applications of CFD models for simulating large stirred slurry reactors.
This paper describes the simulation of the operating environment of the New York Power Pool (NYPP) within the Dispatcher Training Simulator facility at the New York State Electric and Gas Corporation (NYSEG). The NYSEG control center uses real-time data received from the NYPP control center to control its internal generation. In addition, the NYSEG dispatchers work very closely with the NYPP dispatchers. The exact emulation of the Generation Control functions of the NYPP EMS, and the associated data exchange with the NYSEG ECS, contribute greatly to the high degree of realism achieved in the NYSEG DTS facility. The accuracy of the power system simulation in the DTS has been validated against actual power system disturbances recorded at NYSEG.
In this paper the simulation of hybrid processes containing membrane units will be discussed. For this purpose a user-defined module for simulation and design of membrane processes was implemented into the simulation program AspenPlus. The advantages can be summarized as follows: - any combination of membrane processes with all other units already implemented in AspenPlus is possible, including internal recycle streams, - utilization of the physical property models and data bases of AspenPlus is possible, - cost and sensitivity analysis can be performed. These benefits are demonstrated in detail for a membrane vapor recovery unit for the treatment of tank farm off-gas, for a two-stage reverse osmosis plant for organic/-organic separations and for a combination of distillation and pervaporation for the separation of a dimethylcarbonate/methanol mixture. (orig.)
In this book are found technical and scientific papers on the main works of the Direction of the Fuel Cycle (DCC) in France. The study fields are: the up-side of the nuclear fuel cycle with theoretical studies (plasma simulation) and technological developments and instrumentation (lasers diodes, carbides plasma projection, carbon 13 enrichment); the down-side nuclear fuel cycle with theoretical studies (ion Eu{sup 3+} complexation simulation, decay simulation, uranium and plutonium diffusion study, electrolyser operating simulation), scenario studies ( recycling, wastes management), experimental studies; dismantling and cleaning (soils cleaning, surface-active agent for decontamination, fault tree analysis); analysis with expert systems and mass spectrometry. (A.L.B.)
This guide describes the simulator`s governing equations, constitutive functions and numerical solution algorithms of the STOMP (Subsurface Transport Over Multiple Phases) simulator, a scientific tool for analyzing multiple phase subsurface flow and transport. The STOMP simulator`s fundamental purpose is to produce numerical predictions of thermal and hydrologic flow and transport phenomena in variably saturated subsurface environments, which are contaminated with volatile or nonvolatile organic compounds. Auxiliary applications include numerical predictions of solute transport processes including radioactive chain decay processes. In writing these guides for the STOMP simulator, the authors have assumed that the reader comprehends concepts and theories associated with multiple-phase hydrology, heat transfer, thermodynamics, radioactive chain decay, and nonhysteretic relative permeability, ...
The impact of the azimuthal wave refraction in the middle atmosphere on the distribution of gravity wave amplitudes, propagation azimuths, and other wave parameters is investigated using a numerical ray-tracing model of gravity wave propagation through a representative zonal mean reference model of geostrophic winds and temperature in the middle atmosphere. Simulations are first performed with only a single type of gravity wave to help explain some important effects which occur during the refraction process. Then, a multiray simulation is performed which traces a crude spectrum of waves from different altitudes through the atmosphere for every month of a climatological year. The simulated wave climatologies are compared with observations. 108 refs.
Abstract The electrochemical properties of a perfluorosulfonic acid (PFSA) membrane are estimated using a combination of molecular dynamics simulation and statistical thermodynamic model. We obtain all parameters in an ionic conductivity model from an atomistic simulation and remove all adjusted model parameters. From a microscopic point of view, the hydrated PFSA membrane shows micro-phase segregation which separated into hydrophilic and hydrophobic phases. Our present work originates with this phenomenon and we treat this phase segregation as if it is a continuous phase for each of which the proton (H+) is transported inside the PFSA membrane/solvent (water and alcohols) mixture. The chemical potential for a given system is estimated using a molecular simulation technique to predict the ...
terms of 11) numerical models, 2D SPH simulations, and analytic models. The 1D model was useful for determining the evolution over very long timescales. ...
... one for each node, and an i/o queue to manage ... ecuted as if it came from a terminal attached to a ... In its default mode PC-NETSIM is stochastic, that is ...
RODbaffle heat exchanger is a kind of shell-and-tube heat exchanger with eminent performance. Because of the characteristics of tube bundle support structure, fluid flow on shellside is longitudinal and periodical, and fluid flow is of symmetry in landscape orientation. According to the fluid flow characteristics on shellside and ignoring the impact of inlet, outlet and shell wall, a periodic flow unit duct was taken as the simplified model of the shellside to perform numerical simulation by using CFD code, FLUENT. It was found that the both errors in magnitude of the main fluid velocities and heat transfer coefficients between results of simulation and that of experiment or correlations are less than 10%, and the errors of pressure drop between simulation and correlation are no more than 20%. The detailed characteristics and relation of fluid flow and heat transfer on shellside of the RODbaffle heat exchanger were analyzed ...
... that range from relatively low frequency strong ground motion modeling [Vidale et al., 1985] to high frequency reverse time migration of seismic ...
... being pulled out of water, the movement is restricted ... This heating depended on the particle size ... hydrometeor injection into the upper tropopause. ...
Data on French nuclear electricity generation sites, nuclear power plant operations personnel, operation simulators, nuclear training centers and training statistics are presented.
A non-dissipative drift kinetic simulation scheme, which rigorously satisfies the time-reversibility, is applied to the three-mode coupling problem of the ion temperature gradient (ITG) instability. It is found from the simulation that the three-mode ITG system repeats growth and decay with a period which shows a logarithmic divergence for infinitesimal initial perturbations. Accordingly, time average of the mode amplitude vanishes, as the initial amplitude approaches to zero. An exact solution is analytically given for a class of initial conditions. An excellent agreement is confirmed between the analytical solution and numerical results. The results obtained here provide a useful reference for basic benchmarking of theories and simulation of the ITG modes. (author)
To evaluate soil erodibility under different land uses and to study the applicability of nomograph for estimation of soil erodibility a field experiment was conducted under both natural and simulated rainfall conditions under four land uses viz. barren, cultivated, grassland, and forest in the sub-mountainous tract of Punjab (India). Measured soil erodibility (K) values varied from 033 to 067 under natural rainfall conditions and from 023 to 040 under simulated rainfall conditions. Among different land uses, measured K was in the order of barren > cultivated > grassland > forest soils. The values of the K estimated by nomograph were very low as compared to the observed values. The trends were also in contrast to these observed values of K under simulated and natural rainfall conditions. To...
Due to size and costs of big slewing rings, the common methods of experimental trial and error together with destructive test methods for verification of the inductive hardening process are limited. Thereby it is essential to simulate the hardening process in addition to the tests. With these simulations, it should be possible to get conclusions for the hardening pattern, the residual stress and distortion. With actually existing methods a fully three dimensional simulation is extremely time consuming. For that reason, a new method was developed that combines two dimensional with three dimensional simulation to shorten the time for calculation tremendously. (orig.)
Stochastic models for the simulation of global radiation are discussed. Thermal transients in the ground are analyzed. The performance of buried-pipe storage and a space heating system with long-term storage is described.
The utilization of electrically heated rods for the simulation of nuclear fuel pins represents a generally adopted method by the nuclear industry to study thermalhydraulic problems. Usually its is necessary to determine the time variation of the electric linear power to simulate a given nuclear power transient in order to yield the same temperature and heat flux conditions in the surface of the electrical heater that would be observed in the nuclear fuel pin. The present work analyzes the limits of the usually adopted simulation methods and shows a manner to obtain the required electrical linear power that reduces oscillations and yields accurate results for the thermal conditions of the rod surface wall. (author). 5 refs, 5 figs, 1 tab.
The utilization of electrically heated rods for the simulation of a nuclear fuel pins represents a generally adopted method by the nuclear industry to study thermalhydraulic problems. Usually, it is necessary to determine the time variation of the electric linear power to simulate a given nuclear power transient in order to yield the same temperature and heat flux conditions in the surface of the electrical heater that would be observed in the nuclear fuel pin. The present work analyses the limits of the usually adopted simulation methods and shows a manner to obtain the required electrical linear power that reduces oscillations and yields accurate results for the thermal conditions of the rod surface wall. (author) 5 refs., 5 figs., 1 tab.
... AGARD AR-319, Volume 2. Knight, D., Zhou ... a Turbulent Boundary Layer in a Supersonic Flow. ... of Development of Separated Flows in Compression ...
... turbine blade heat-transfer and study the heat-transfer augmentation in idealized geometry and its ... responsible for heat transfer augmentation. ...
Aug 18, 2004 ... The Arabian Gulf region presents a challenge to meteorologists trying to simulate weather with computer models because sea-surface and land ...
The results obtained from experimental investigations and mathematical simulation of horizontal steam generators are considered. Recommendations for continuing these works are given.
Mar 15, 2011 ... Information Technology. NCCS Discover Supercomputer. Science mission data collection, analysis and simulations pose unprecedented computer ...
We have simulated the transient enhanced diffusion (TED) of boron fluoride (BF_2"+) implanted in crystalline and germanium amorphized silicon. Based on recently published models, the effect of fluorine on boron diffusion in silicon has been introduced and a modelling has been suggested. In order to simulate the boron experimental profiles, we have assumed that fluorine forms clusters involving interstitial boron which reduces the junction depth. Experimental results indicate that fluorine behaviour depends on amorphization energy. Moreover, even no germanium preamorphization is performed, silicon is still amorphized by fluorine species. Hence, BF_2"+ implantation leads to an amorphous/crystalline (a/c) interface near the surface. An improvement of published models is suggested taking into account fluorine effects. The simulations satisfactory reproduce the SIMS experimental profiles for a large scale of experimental ...
Jan 12, 2010 ... Visual simulation of offshore liquefied natural gas (lng) terminals in a decision-making context. Baird, Brian E.; Sheppard, Stephen R. J.; ...
In this paper we present a model and simulator for many clusters of heterogeneous PCs belonging to a local network. These clusters are assumed to be connected to each other through a global network and each cluster is managed via a local scheduler which is shared by many users. We validate our simulator by comparing the experimental and analytical results of a M/M/4 queuing system. These studies indicate that the simulator is consistent. Next, we do the comparison with a real batch system and we obtain an average error of 10.5\\% for the response time and 12\\% for the makespan. We conclude that the simulator is realistic and well describes the behaviour of a large-scale system. Thus we can study the scheduling of our system called \\dirac in a high throughput context. We justify our decentralized, adaptive and opportunistic approach in comparison to a centralized approach in such a context.
An impingement jet system was used to study flow-assisted corrosion (FAC) of 3003 aluminum (Al) alloy in ethylene glycol-water solutions that simulates the automotive coolant by corrosion potential and electrochemical impedance spectroscopy (EIS) measurements as well as computational fluid dynamics (CFD) simulation. The effects of solution pH and fluid impact angle on Al FAC were determined. An increase of solution pH enhances the activity of Al due to dissolution of Al oxide film in alkaline environment. Moreover, Al activity decreases with the increasing fluid impact angle to the specimen. A CFD simulation shows that, with the increase of impact angle, the electrode area under high-velocity flow field decreases and that under low-velocity flow field increases. Consequently, the shear str...
Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based...Full Text Available
A complete analysis is performed to simulate biomass production incorporated into a realistic whole farm situation, including or replacing a typical crop mix. Representative farms are constructed to accommodate such simulation. Four management systems are simulated for each firm, with each simulation depicting a different crop mix and/or use of different farming technologies and production methods. The first simulation was a base farm plan in which the operator would maintain the historical crop mix for the area, participate in all price support programs, and not participate in either a conservative reserve or a biomass production program. In the second simulation, the operator would again maintain the historical crop mix, would not participate in a conservation reserve or biomass production program, and would be ineligible to participate in any price support ...
A complete analysis is performed to simulate biomass production incorporated into a realistic whole farm situation, including or replacing a typical crop mix. Representative farms are constructed to accommodate such simulation. Four management systems are simulated for each firm, with each simulation depicting a different crop mix and/or use of different farming technologies and production methods. The first simulation was a base farm plan in which the operator would maintain the historical crop mix for the area, participate in all price support programs, and not participate in either a conservative reserve or a biomass production program. In the second simulation, the operator would again maintain the historical crop mix, would not participate in a conservation reserve or biomass production program, and would be ineligible to participate in any price support ...
The aims of the present work were to investigate possible compatibility between sodium zirconium phosphate (NZP) and Synroc titanate phases, to prepare NZP-based waste forms by hot-pressing rather than sintering, and to investigate the incorporation in NZP of (a) Cs/Sr as simulated heat-generating nuclides; (b) simulated actinides; and (c) simulated Purex waste. The NZP samples were prepared by methods similar to those used for Synroc. The precursor NZP phase was formed from tetrabutyl zirconate Zr(OC{sub 4}H{sub 9}){sub 4}, sodium nitrate, and 85% orthophosphoric acid. Simulated waste nitrate solutions were then mixed with the liquid precursor. After stir drying of the precursor, calcination was carried out at 700{degree}C to remove nitrates and organics.
7.5.6 Conclusions of the Generic Metroplex Queueing Simulation . ...... the systemwide arrival delays incurred at the metroplex terminal-area ...... assignment rules, estimated nominal transit speeds or times by domain, and stochastic ...
We present results of multiple-time-scale simulations of 5, 10 and 15 keV low temperature ion implantation of arsenic on silicon (100), followed by high temperature anneals. The simulations start with a molecular dynamics (MD) calculation of the primary state of damage after 10ps. The results are then coupled to a kinetic Monte Carlo (MC) simulation of bulk defect diffusion and clustering. Dose accumulation is achieved considering that at low temperatures the damage produced in the lattice is stable. After the desired dose is accumulated, the system is annealed at 800 degrees C for several seconds. The results provide information on the evolution for the damage microstructure over macroscopic length and time scales and affords direct comparison to experimental results. We discuss the database of inputs to the MC model and how it affects the diffusion process.
Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and...
... which may have embedded remote terminals, and (4 ... model the time-variant or stochastic aspects of ... on such system parameters as queue size, time ...
This paper presents a new approach to improve the in silico modeling of ultrasound transducer arrays. While current simulation tools accurately predict the theoretical element...Full Text Available
Engine model: An engine and governor model adapted from a heavy lift helicopter simulation provides a restistic time delay between aerodynamic rotor ...
... 1 1 if on-line printout is desired (data will also be stored on tape) = 0 or blank, reduced data will be stored on a listable tape P3 M Codes B - Corivert ...
joint task force (JTF), division (OIV) and regimental combat team (RCT) with ..... Headquarters, Department of the Army. (HQOA), (2010). Field Manual 2-0 ...
The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the surety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering (D&E) programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment ...
The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with current and future nonnuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program requires the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing Program (ASC)1 is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and ...
A large number of proven technical solutions exists for the use of renewable energies (RE). However, their dissemination is still too slow to meet the political goal of substituting 12 % of the primary energy demand in the European Union by the year 2010. Even renewable energy systems (RES) with economic potential are only partly exploited. There is a long literature concerning the barriers to RE use. In particular it has become clear that the availability of finance and the forms and conditions upon which it is lent have a major impact on RE deployment. An area of importance is the deficiency of appropriate ownership forms and properly adapted financing instruments in certain countries. Moreover, different regulations and institutional barriers in the European countries hinder the free flow of capital for RES within the European common market. On the other hand, solutions have been developed very successfully in individual countries. Differences in cultures and ...
To further optimize thermo-hydraulic capability of HCSB-TBM, two different thermo-hydraulic schemes would be proposed and investigated by relevant calculating and simulating of thermo-dynamics in normal and peak heat flux condition. With computational fluid dynamics (CFD) code FLUENT, the actual temperature distribution of key components of HCSB-TBM is simulated. (authors)
The rare earth antimonates RE_3Sb_5O_1_2 constitute an isostructural series, where the rare earth site symmetry is S_4. The spectroscopic properties of pure or doped compounds of this family are studied in order to derive their energy level schemes and to simulate them through the crystal field theory, by using the approximated D_2_d potential. The paramagnetic susceptibilities are calculated with the derived wavefunctions and compared to experiment.
We demonstrate a two-dimensional device simulator for MOSFET structures that incorporates models for defect distributions and show predicted effects on device switching performance for various spatial distributions of defects in amorphous and polycrystalline silicon.
This report describes the test of a dynamic phase compensation unit for a wind turbine with directly connected induction generators. The compensation unit is based on thyristor switched capacitors, where conventional wind turbine compensations use mechanical contactors to switch the capacitors. The influence on power quality analysed, and influence on component lifetime is discussed. Besides, simulation models in Matlab/Simulink are presented, including a flicker meter model. (au)
Symplectic integrators designed for simulating soft matter at constant temperature and constant pressure (or constant surface tension) are presented. In addition to the well-known merits of symplectic integrators, such as long time stability, these methods allow the estimation of thermal heat production/absorption and thus entropy differences through a simple function of the time scaling factor ?. The relative entropy estimation around crystal-liquid phase transition is given for systems with soft core repulsive potential.
Gas and stars in spiral galaxies are modelled with the DUAL code, using hydrodynamic and N-body techniques. The simulations reveal morphological differences mirroring the dual morphologies seen in B and K' band observations of many spiral galaxies. In particular, the gaseous images are more flocculent with lower pitch angles than the stellar images, and the stellar arm-interarm contrast correlates with the degree of morphological decoupling.
The peculiarities of pulsed laser melting and evaporation of the superconducting ceramics are analyzed by means of numerical simulation. The appearance of the overheated metastable states in solid and liquid phases is shown as a result of the phase front dynamics and volume nature of laser energy release. A method of dynamic adaptation for the multifront Stefan problem is proposed.
The model of transient enhanced diffusion of ion-implanted As is formulated and the finite-difference method for numerical solution of the system of equations obtained is developed. The nonuniform distribution of point defects near the interface and more accurate description of arsenic clustering are simultaneously taken into account. Simulation of As diffusion during rapid annealing gives a reasonable agreement with the experimental data. (authors)
Computer simulations and experiments indicate that we can shape the infrared picosecond pulses of the Mark III FEL in amplitude, frequency, and phase. Strongly modulated fundamental and second harmonic pulses have been generated by operating the Mark III FEL in the regime of strong sideband growth. In this paper, we present the results of simulations and experiments for second harmonic generation with fundamental inputs from 2 to 3 {mu}m.
The paper deals with a model in which the motion of a gas in plasma accerators and high-curent discharges in the present of a skin effect is treated as expulsion by a 'magnetic piston' under the action of surface current flow. Specifically examined is the situation where the initial gas pressure is negligible in comparison with the magnetic pressure, and the motion of the gas may be treated as a self-simulating one. A system of hydrodynamic equations of the problem is derived and integrated by Adam's method. Results are plotted and discussed.
A reliable inventory control system was developed at the Fast Flux Test Facility (FFTF) to keep track of the occupancy of 900 refueling facility locations, to compile historical data on the movement of each reactor assembly, and to simulate assembly moves. The simulate capability is valuable because it allows verification of documents before they are issued for use in the plant, and eliminates the possibility of planning illegal or impossible moves. The system is installed on a UNIVAC 1100 computer and is maintained using a data base management system by Sperry Univac called MAPPER.
There is need of pressure surge analyses when valves or pumps are activated or piping systems fail (pipe rupture). Based on actual problems the influences of boundary conditions upon fluid simulation results are discussed. Hints concerning realistic dynamic analyses of piping systems are presented. Some of the simulations results are compared with measurements. (orig.)
This is an inquiry-based module created specifically for use with the PhET simulation Geometric Optics. It includes a lesson plan for teaching about convex lenses, step-by-step student directions, and a set of Power Point "clicker" questions for use as warm-up questions or informal assessment. This resource is part of a larger collection of interactive Java simulations for students of physics, developed by the Physics Education Technology project at the University of Colorado.
Performance predictions have been made for attached-sunspace types of passively solar heated buildings. The predictions are based on hour-by-hour computer simulations using computer models developed in the framework of PASOLE, the Los Alamos Scientific Laboratory (LASL) passive solar energy simulation program. The models have been validated by detailed comparison with actual hourly temperature measurements taken in attached-sunspace test rooms at LASL.
A physical model of free-electron laser (FEL) amplifier with variable-parameter wiggler magnets for one-dimensional numerical simulation is presented and a numerical example is given. The wiggler parameters, efficiency of energy conversion between electron beam and laser field, laser intensity, phase-space distributions and energy spectrum of electrons are computed. The period of synchronous oscillation and saturation value of laser intensity agree with estimated one.
The Monte Carlo simulation method is applied to calculate the nucleon transfer part of the imaginary optical-model potential in colliding heavy ions. In the process of transfer of nucleons from one nucleus to the other, forward and backward neutrons and protons are treated separately by taking into consideration the effect of the Coulomb forces and the potential energy surfaces (driving forces). The Pauli exclusion principle is also incorporated properly in the calculation.
A Siemens Mevatron KV2 accelerator installed at the Royal Adelaide Hospital employs cylindrical solid-walled electron cones for some electron collimation. The cones being used at present result in treatment fields that do not always conform with the International Electrotechnical Commission (IEC) Standards (particularly at high energies). The aim of this project was to simulate the existing cones using Monte Carlo methods in order to evaluate potential cone modifications required to overcome the field irregularities. Simulations were performed using the EGS4 (Electron Gamma Shower version 4, distribution II) Monte Carlo code installed on a DEC Alpha workstation at the University of South Australia. To rigorously simulate the existing electron cones it was necessary to also simulate various components within the treatment head of the linear accelerator. Results of simulations for ...
Molecular simulation aims at simulating particles in interaction, describing a physico-chemical system. When considering Markov Chain Monte Carlo sampling in this context, we often meet the same problem of statistical efficiency as with Molecular Dynamics for the simulation of complex molecules (polymers for example). The search for a correct sampling of the space of possible configurations with respect to the Boltzmann-Gibbs distribution is directly related to the statistical efficiency of such algorithms (i.e. the ability of rapidly providing uncorrelated states covering all the configuration space). We investigated how to improve this efficiency with the help of Artificial Evolution (AE). AE algorithms form a class of stochastic optimization algorithms inspired by Darwinian evolution. Efficiency measures that can be turned into efficiency criteria have been first searched before identifying parameters that could be ...
Molecular dynamics computer simulations of a dense nanocrystalline Nickel sample are performed on the parallel Cray T3 (EPFL-Lausanne). The sample contains 50 grains with an average size of 3 nm. By perturbing the relaxed configuration elastic and plastic properties are studied. (author) 1 fig., 1 ref.
The point-defect-impurity pair diffusion model proposed recently by Mulvaney and Richardson is adopted and modified to simulate the coupled diffusion of phosphorus and self-interstitials in phosphorus-implanted silicon. The assumption of implantation-induced, but empirically determined initial interstitial distributions of Gaussian shape allows a simulation of the net effect of transient enhanced diffusion. As a result an improved modeling of phosphorus diffusion in silicon is achieved for a broad range of ion-implantation and annealing conditions. (author).
We study the dynamical evolution of globular clusters containing primordial binaries, including full single and binary stellar evolution using our Monte Carlo cluster evolution code updated with an adaptation of the single and binary stellar evolution codes SSE and BSE from Hurley et al. We describe the modifications that we have made to the code. We present several test calculations and comparisons with existing studies to illustrate the validity of the code. We show that our code finds very good agreement with direct N-body simulations including primordial binaries and stellar evolution. We find significant differences in the evolution of the global properties of the simulated clusters using stellar evolution compared with simulations without any stellar evolution. In particular, we find that the mass loss from the stellar evolution acts as a significant energy production channel simply by reducing the total gravitational ...
A series of first principles molecular dynamics and Monte Carlo simulations were carried out for liquid water to assess the validity and reproducibility of different sampling approaches. These simulations include Car-Parrinello molecular dynamics simulations using the program CPMD with different values of the fictitious electron mass in the microcanonical and canonical ensembles, Born-Oppenheimer molecular dynamics using the programs CPMD and CP2K in the microcanonical ensemble, and Metropolis Monte Carlo using CP2K in the canonical ensemble. With the exception of one simulation for 128 water molecules, all other simulations were carried out for systems consisting of 64 molecules. It is found that the structural and thermodynamic properties of these simulations are in excellent agreement with each other as long as adiabatic sampling is maintained in the ...
In order to investigate the extrusion characteristics of magnesium alloy (AZ31), a computer simulation was attempted. Tensile properties of as-cast billet with different strain rates were incorporated into the simulation. The results showed a great change in distribution of stress and strain at near die region by the ram travel. It was found that the average grain size at longitudinal edge of the extruded sheet was smaller than that at center region, which might be attributed to recrystallization caused by severe plastic deformation. (orig.)
Two TNT high explosives simulants have been developed. Small scale testing has shown them to be insensitive to: impact, spark, friction, temperature, and shock. The materials have been scaled to 0.5 kg quantities and samples given to the Protective Services Department for field evaluation using explosives detecting canines.
The continuous bioprocessing of simulated steam-stripped sulfite pulp mill evaporator condensates using Candida utilis to produce single cell protein has been studied. At 32 degrees C, processing can be conducted at space velocities of up to 0.43 hr/sup -1/ with over 90% removal of acetic acid present at an initial concentration of 2 g/liter. (Refs. 16).
A new algorithm for the treatment of sliding interfaces between solids with or without friction in an Eulerian wavecode is described. The algorithm has been implemented in the two-dimensional version of the CTH code. The code was used to simulate penetration and perforation of aluminum plates by rigid, conical-nosed tungsten projectiles. Comparison with experimental data is provided.
Interaction of drilling fluids with a geothermal reservoir formation can result in significant permeability impairment and therefore reduced well productivity. This interaction is studied under simulated in situ geothermal conditions of overburden stress, pore fluid pressure, temperature, and pore fluid chemistry. Permeability impairment of an East Mesa KGRA reservoir material is evaluated as a function of stagnation time, drilling fluid, and temperature. Results indicate that all of these parameters contribute significantly to the magnitude and the reversibility of the impairment.
Simulations of young stellar systems suggest that planets embedded in a circumstellar disk can produce many distinctive structures, including rings, gaps and spiral arms. This video compares computer simulations of hypothetical systems to an image of system SAO 206462 taken by the Subaru Telescope and its HiCIAO instrument. n nCredit: NASA Goddard Space Flight Center/NCSA
Power devices such as MOSFETSs and IGBTs, include parasitic structures that can give rise to destructive failures such as breakdown and latch-up. To determine a suitable strategy for device radiation hardening, simulation software like MEDICI-2D can be used to model the effects of technological modifications and device parameters that are difficult to measure experimentally. (authors).
The corrosion rate of low alloy steel SA-508 and carbon steel A-410b in simulated operation and shutdown conditions of pressurized water reactor has been determined Moreover potentiodynamic polarization curves and galvanic effect through coupling of AISI-304 have been carried out under shutdown simulated condition. (Author) 8 refs.
Taking both white noise and colored environmental noise into account, a general stochastic logistic model under regime switching is proposed and studied. Sufficient conditions for extinction, nonpersistence in the mean, weak persistence, stochastic permanence and global attractivity are established. The critical number between weak persistence and extinction is obtained. Moreover, some simulation figures are introduced to illustrate the main results.
This work deals with a time-resolved optical study of the avalanche and streamer formation phases leading to breakdown in atmospheric nitrogen. The authors present the results obtained for nitrogen, from experiments and two-dimensional model simulations. This model is used to obtain a better insight in the relevant mechanisms and processes by a comparison of measurements and simulation data. The trends of externally measured quantities correspond with those predicted by the model.
A simple and continuous model for the on-state current of polysilicon thin-film transistors, suitable for implementation in circuit simulators, is presented. The model includes the potential barrier at the grain boundaries, the channel length modulation and the excess current due to impact ionization. Comparison between measured output characteristics and the model shows excellent agreement over wide range of bias voltages and for devices with different gate lengths.
In this paper, finite-difference time-domain method is used to research the transient electromagnetic pulse (EMP) coupling to the cylinder object which is shielded in another shielding cavity with a hole numerically. The different coupling effectiveness of three transient EMP is simulated. The distribution of the electric field in the shielding cavity and the current on the cavity are researched. The shielding effectiveness is evaluated. (authors)
This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users Guide. The Xyce Parallel Electronic Simulator has been written to support, in a rigorous manner, the simulation needs of the Sandia National Laboratories electrical designers. It is targeted specifically to run on large-scale parallel computing platforms but also runs well on a variety of architectures including single processor workstations. It also aims to support a variety of devices and models specific to Sandia needs. This document is intended to complement the Xyce Users Guide. It contains ...
The He-shell flash convection in AGB stars is the site for the high-temperature component of the s-process in low- and intermediate mass giants, driven by the Ne22 neutron source. [...] The upper convection boundary plays a critical role during the H-ingestion episode that may lead to neutron-bursts in the most metal-poor AGB stars. We address these problems through global 3-dimensional hydrodynamic simulations including the entire spherical He-shell flash convection zone (as oposed to the 3D box-in-a-star simulations). An important aspect of our current effort is to establish the feasibility of our appoach. We explain why we favour the explicit treatment over the anelastic approximation for this problem. The simulations presented in this paper use a Cartesian grid of 512^3 cells and have been run on four 8-core workstations for four days to simulate ~5000s, which corresponds to almost ten convective ...
We develop a 3-D model to simulate the synthetic aperture radar (SAR) image formation process of an undulated vegetation canopy such as corn grown in fields with large periodic drainage reliefs. We explain how the simulated SAR image of undulated vegetation medium is obtained by the convolution of a 2-D slice of the 3-D simulated SAR system point spread function [(PSF), emulating the SAR beam modeled by a cosine modulated Gaussian], with the 2-D projection of the observed undulated vegetation canopy (modeled with scatterers randomly distributed in 3-D undulated space) followed by the extraction of each look envelope, the summation of looks, and sampling in azimuthal and range directions. Our model is useful to study the parameters involved in the formation and the analysis of SAR images of undulated vegetation medium. Validation of simulations made with actual SAR images shows that undulated corn crop ...
We present results from a large volume simulation of Hydrogen reionization. We combine 3d radiative transfer calculations and an N-body simulation, describing structure formation in the IGM, to detail the growth of HII regions around high redshift galaxies. Our simulation tracks 1024^3 dark matter particles, in a box of side length 65.6 Mpc/h. This large volume allows us to accurately characterize the size distribution of HII regions throughout most of the reionization process. At the same time, our simulation resolves many of the small galaxies likely responsible for reionization. It confirms a picture anticipated by analytic models: HII regions grow collectively around highly-clustered sources, and have a well-defined characteristic size, evolving from a sub-Mpc scale at the beginning of reionization to R>10 Mpc towards the end. We present a detailed statistical description of our results, and ...
This paper describes the graphical simulation of a traffic environment. The environment includes streets leading to an intersection, the intersection, vehicle traffic, and signal lights in the intersection controlled by different methods. The simulation allows for the study of parameters affecting traffic environments and the study of different control strategies for traffic signal lights, including conventional, fuzzy, and adaptive control methods. Realistic traffic environments are simulated including a cross intersection, with one or more lanes of traffic in each direction, with and without turn lanes. Vehicle traffic patterns are a mixture of cars going straight and making right or left turns. The free velocities of vehicles follow a normal distribution with a mean of the ``posted`` speed limit. Actual velocities depend on such factors as the proximity and velocity of surrounding traffic, approaches to intersections, ...
Numerical simulations predict that a large number of baryons reside in intergalactic space at temperatures between 10^5-10^7 K. Highly-ionized metals, such as O VII and O VIII, are good tracers of this ``warm-hot intergalactic medium'', or WHIM. For collisionally-ionized gas, the ionization fraction of each ion peaks at some particular temperature (``peak temperatures''), so different ions can therefore trace the IGM at different temperatures. We performed a hydrodynamic simulation to study the metal distributions in the IGM. We then draw random lines-of-sight across the simulated region and synthesize resonance absorption line spectra in a similar way to simulating the Ly-alpha forest. By studying the distribution functions of H- and He-like O, Si and Fe in a collisionally-ionized IGM and comparing with semi-analytic results based on the Press-Schechter formalism, we find: (1) ions with higher peak ...
The improvement in the functions of the viscous flow calculation method VEGA-SHIP around a ship and the expansion of application range were described as the numerical flow simulation in ship and ocean engineering and at the same time application examples to the ocean engineering by the general-purpose flow simulation code FLOW-3D handling the non-steady flow with a free surface were introduced as the numerical simulation regarding such products as a water gate and a dam. In the VEGA-SHIP, water surface was handled as a fixed wall so that wave could not be calculated. Therefore, an algorithm for calculating wave on the water surface was added to the VEGA-SHIP and a calculation method simultaneously considering the creation of wave around the ship and viscosity was developed. The FLOW-3D was used to calculate the phenomenon where inside liquid moved greatly due to the oscillation of a tank and hit against and damaged the tank ...
The three-dimensional (3-D), multiphase, computational fluid dynamic (CFD) code FLUENT is used to simulated two-phase flow behaviour in a CANDU header manifold under low (natural circulation) flow conditions. This behaviour was previously inferred from experimental data. The CFD simulations reported here are being used to support these inferences and to obtain a better understanding of phase distribution in the header manifold. The simulations seem to show that the vapor-water mixture models in the FLUENT code do not capture properly phase separation in the header and proper phase branching at the header-feeder connections that have been observed in experiments at low flows. The simulations using discrete-phase model in FLUENT, which tracks the pathlines of the individual vapor bubbles in the water continuum phase, show interesting, complicated and, in some cases, unexpected bubble trajectories from the ...
The Stockpile Stewardship Program (SSP) is a single, highly integrated technical program for maintaining the safety and reliability of the U.S. nuclear stockpile. The SSP uses past nuclear test data along with future non-nuclear test data, computational modeling and simulation, and experimental facilities to advance understanding of nuclear weapons. It includes stockpile surveillance, experimental research, development and engineering programs, and an appropriately scaled production capability to support stockpile requirements. This integrated national program will require the continued use of current facilities and programs along with new experimental facilities and computational enhancements to support these programs. The Advanced Simulation and Computing program (ASC) is a cornerstone of the SSP, providing simulation capabilities and computational resources to support the annual stockpile assessment and certification, to ...
(Abridged) We use 3D SPH calculations with higher resolution, as well as with more realistic viscosity and sound-speed prescriptions than previous work to examine the eccentric instability which underlies the superhump phenomenon in semi-detached binaries. We illustrate the importance of the two-armed spiral mode in the generation of superhumps. Differential motions in the fluid disc cause converging flows which lead to strong spiral shocks once each superhump cycle. The dissipation associated with these shocks powers the superhump. We compare 2D and 3D results, and conclude that 3D simulations are necessary to faithfully simulate the disc dynamics. We ran our simulations for unprecedented durations, so that an eccentric equilibrium is established except at high mass ratios where the growth rate of the instability is very low. Our improved simulations give a closer match to the observed relationship ...
In a Pb-Bi cooled direct contact steam generation fast reactor water is injected directly above the core, the produced steam is separated at the top and is send to the turbine. Neither the direct contact phenomenon nor the two-phase flow simulations in CFD have been thoroughly described yet. A first attempt in simulating such two-phase flow in 2D using the CFD code Fluent is presented in this paper. The volume of fluid explicit model was used. Other important simulation parameters were: pressure velocity relation PISO, discretization scheme body force weighted for pressure, second order upwind for momentum and CISCAM for void fraction. Boundary conditions were mass flow inlet (Pb-Bi 0 kg/s and steam 0.07 kg/s) and pressure outlet. The effect of mesh size (0.5 mm and 0.2 mm cells) was investigated as well as the effect of the turbulent model. It was found that using a fine mesh is very important in order to achieve larger ...
Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...
Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...
Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints ...
This paper presents a new methodology to create realistic 3D microstructures of polycrystals. The virtual microstructures are based on statistical data describing the morphological and crystallographic textures of a sample, obtained from an EBSD analysis. In addition, the methodology can reproduce the observed surface on top of the simulated microstructure. This feature allows finite element calculations on these virtual aggregates to be compared to experimental results of mechanical tests. Such a comparison leads to the identification of the mechanical parameters of constitutive laws, such as critical resolved shear stress and strain hardening, using an optimization algorithm. Two materials were simulated in this study: TiAl and grade 702 zirconium. The first one presents twins inside the microstructure and the second one has an anisotropic texture. Based on 2D simulations, the important parameters necessary to describe a ...
This thesis - Resource Management in Broadband Communication Networks - deals with different ways of optimizing the available resources of data- or telecommunication networks. Especially topics like optimal routing, load balancing and fast recovery of routes in case of link failures are covered. The first part gives a brief description of some of the existing protocols for routing and controlling resources, such as RSVP, OSPF, BGP, PNNI, etc. The remaining part concerns the following two fundamentally different approaches to resource management etc.: - Software agents - Simulated ants In the beginning of the part concerning software agents a description of what exactly constitutes software agents, according to the scientists and according to the organization, FIPA is given. After this, the main results from the IMPACT project are presented. The IMPACT project is an EU-project that aimed at developing a demonstration platform, where software agents handled virtually ...
This book proposed that a post-2012 climate regime will need to balance the needs of all countries while aiming to prevent the potentially serious economic and social consequences of the impacts of climate change. Four elements were presented to support the emergence of an internationally acceptable approach: (1) the need to ensure sustainable economic development; (2) the effective development and penetration of clean technologies; (3) the establishment of an effective international carbon market over the long term; and (4) the integration of adaptation in development and natural resource management decision-making. A series of discussion papers were presented which reviewed options on how best to create an effective and inclusive international climate regime that will achieve large reductions in global emissions and equitably reflect the diverse circumstances of countries while promoting sustainable economic development. The first paper highlighted some of the characteristics of an ...
The mass deployment of electric and plug-in hybrid electric vehicles (EVs and PHEVs) that rely on low greenhouse gas (GHG) emission electricity generation has great potential to significantly reduce the consumption of petroleum and other high CO2-emitting transportation fuels. The vision of the Electric and Plug-in Hybrid (EV/PHEV) Vehicles Roadmap is to achieve by 2050 the widespread adoption and use of EVs and PHEVs, which together represent more than 50% of annual LDV (light duty vehicle) sales worldwide. In addition to establishing a vision, this roadmap sets strategic goals to achieve it, and identifies the steps that need to be taken to accomplish these goals. This roadmap also outlines the roles and collaboration opportunities for different stakeholders and shows how government policy can support the overall achievement of the vision. The strategic goals for attaining the widespread adoption and use of EVs and PHEVs worldwide by 2050 cover the development of ...
This document presents the results of a review of publicly available information on energy use in health care facilities. The information contained in this document and in the sources cited herein provides the background and context for efforts to reduce energy use and costs in health care. Recognizing the breadth and diversity of relevant information, the author acknowledges that the report is likely not comprehensive. It is intended only to present a broad picture of what is currently known about health care energy use. This review was conducted as part of a 'High Performance Health Care Buildings' research study funded by the California Energy Commission. The study was motivated by the recognition that health care facilities collectively account for a substantial fraction of total commercial building energy use, due in large part to the very high energy intensity of hospitals and other inpatient care facilities. The goal of the study was to develop a roadmap of ...
An update of Toronto Hydro's smart metering program was presented. Electricity demand is expected to keep increasing, and there is presently insufficient generation to match supply needs in Ontario. The smart metering program was introduced to aid in the Ontario government's energy conservation strategy, as well as to address peak supply problems that have led to power outages. It is expected that the smart metering program will reduce provincial peak supply by 5 per cent, as the meters support both time-of-use rates and critical peak pricing. Over 800,000 smart meters will be supplied to customers by 2007, and all 4.3 million homes in Toronto will have a smart meter by 2010. In order to meet targets for 2010, the utility will continue to install more 15,000 meters each month for the next 4 years. While the Ontario government has planned and coordinated the rollout and developed smart metering specifications and standards, Toronto Hydro is responsible for the ...
Full text: Secure, reliable and cost-effective communications are becoming an increasingly important tool for safeguards verification. This trend began with the initiation of remote monitoring implementation, where secure and cost effective data communications were required both to satisfy the confidentiality requirements of Member States and in order to meet the rigorous data authenticity requirements which allow the International Atomic Energy Agency (IAEA) to draw credible and independent conclusions. In addition, the implementation of additional protocols and integrated safeguards increases the importance of information (obtained in the course of an inspection, visit, complementary access or design information verification) being analyzed and corroborated with other information sources stored at IAEA Headquarters or Regional Offices, often while the inspector is still on-site. This requires the capability of enabling the inspector, wherever he is in the field, to communicate with ...
Fusion energy is one of only a few truly long-term energy options. Since its inception in the 1950s, the vision of the fusion energy research program has been to develop a viable means of harnessing the virtually unlimited energy stored in the nuclei of light atoms--the primary fuel deuterium is present as one part in 6,500 of all hydrogen. This vision grew out of the recognition that the immense power radiated by the sun is fueled by nuclear fusion in its hot core. Such high temperatures are a prerequisite for driving significant fusion reactions. The fascinating fourth state of matter at high temperatures is known as plasma. It is only in this fourth state of matter that the nuclei of two light atoms can fuse, releasing the excess energy that was needed to separately bind each of the original two nuclei. Because the nuclei of atoms carry a net positive electric charge, they repel each other. Hydrogenic nuclei, such as deuterium and tritium, must be heated to approximately 100 million ...
Purpose: To evaluate the initial and mid-term results of a new self-expanding low strut profile nitinol stent for treatment of atherosclerotic lesions stenoses and occlusions in the superficial femoral artery (SFA). Materials and Methods: In 8 patients (4 male, 4 female, mean age 74.8 {+-} 8.8 years) with SFA lesions and non-satisfying results after PTA treatment alone, 10 self-expanding nitinol Xpert stents were deployed via a 4 F sheath. Stent characteristics and handling were graded by the interventionalist. Fontaine classification, duplex flow measurements and ankle brachial index (ABI) at rest and stress were taken prior and one day after stent placement. Patients were followed 3, 6 and 12 months after the procedure obtaining the same parameters at each appointment. Results: Initial stent treatment was successful in all patients. Stent handling and positioning were rated very good and safe. All patients improved clinically by at least one Fontaine stage (range ...
Coiling or infusion of embolic materials into a wide necked aneurysm can be performed with stenting. The purpose of our study is to assess the technical feasibility of aneurysm treatment with glue embolization after stenting. We used four Wallstents for surgically repairing eight canine carotid aneurysms. After confirmation of the aneurysms on the angiogram, we introduced a 6-7 F guiding catheter in order to deploy the stents. After stenting, we passed a microcatheter into the aneurysm lumen through the stent mesh. 28% glue was slowly injected until the glue cast completely filled the lumen. We evaluated the passage of a microcatheter through the stent meshwork, formation of the glue cast and the stents' ability to protection for any leakage of glue. The follow-up angiogram was obtained for two dogs, one to three times until 8 weeks, and then we sacrificed the dogs and performed pathologic examinations. Stenting was successful in all cases except one in which the ...
In many parts of the United States, as well as other regions of the world, competing demands for fresh water or water suitable for desalination are outstripping sustainable supplies. In these areas, new water supplies are necessary to sustain economic development and agricultural uses, as well as support expanding populations, particularly in the Southwestern United States. Increasing the supply of water will more than likely come through desalinization of water reservoirs that are not suitable for present use. Surface-deployed seismic and electromagnetic (EM) methods have the potential for addressing these critical issues within large volumes of an aquifer at a lower cost than drilling and sampling. However, for detailed analysis of the water quality, some sampling utilizing boreholes would be required with geophysical methods being employed to extrapolate these sampled results to non-sampled regions of the aquifer. The research in this report addresses using ...
This document is a Final Technical Report that describes the results of the Geophex Airborne Unmanned Survey System (GAUSS) research project. The objectives were to construct a geophysical data acquisition system that uses a remotely operated unmanned aerial vehicle (UAV) and to evaluate its effectiveness for characterization of hazardous environmental sites. The GAUSS is a data acquisition system that mitigates the potential risk to personnel during geophysical characterization of hazardous or radioactive sites. The fundamental basis of the GAUSS is as follows: (1) an unmanned survey vehicle carries geophysical sensors into a hazardous location, (2) the pilot remains outside the hazardous site and operates the vehicle using radio control, (3) geophysical measurements and their spatial locations are processed by an automated data-acquisition system which displays data on an off-site monitor in real-time, and (4) the pilot uses the display to direct the survey vehicle for complete site ...
In 1994, the United States Department of Energy, the United States electric utilities and the geothermal heat pump (GeoExchange) industry formed a non-profit collaborative effort called the Geothermal Heat Pump Consortium (GHPC). The objectives were the reduction and/or elimination of 1.5 million metric tons of carbon equivalent per year and making geothermal heat pumps a significant part of the Heating Ventilation Air Cooling (HVAC) industry. Federal funding of 35 million dollars over six years was matched by 65 million dollars of private sector funds to attain these objectives and create a self-sustainable GeoExchange market. The major accomplishments of this endeavour, as well as the lessons learned were presented in this paper. The infrastructure was strengthened, first cost was reduced, and awareness of the technology was increased over the past six years as a result of the efforts deployed by the GHPC. More than 500,000 units are already installed, which ...
This guide is one of the actions following from the recommendations of the Thermie B project that aimed to support the development of a new European Integrated Clean Coal (CCT) Program concept (STR - 1121 - 96), November 1998. The concept aimed to enhance the market deployment of EU CCTs. This guide is prepared for EU industry to help them finding support for their CCT exports to the target markets. The guide will include easy accessible information on the most relevant EC-programs and is intended as a practical tool for EU CCT industry, to assist them in identifying and selecting the export support and programs best able to support their specific export assistance. The guide is a manual (signpost) through the 'jungle of assistance' and therefore does not include extensive information on application procedures, since this kind of information can be easily obtained, once the relevant program is identified. Also information will be presented on EU ...
The Internet is becoming the preferred method for disseminating scientific data from a variety of disciplines. This can result in information overload on the part of the scientists, who are unable to query all of the relevant sources, even if they knew where to find them, what they contained, how to interact with them, and how to interpret the results. A related issue is keeping up with current trends in information technology often taxes the end-user's expertise and time. Thus instead of benefiting from this information rich environment, scientists become experts on a small number of sources and technologies, use them almost exclusively, and develop a resistance to innovations that can enhance their productivity. Enabling information based scientific advances, in domains such as functional genomics, requires fully utilizing all available information and the latest technologies. In order to address this problem we are developing a end-user centric, domain-sensitive ...
This thesis develops methods for recording and analysis of seismo-acoustic interface waves for determination of shear wave velocity as a function of depth and includes this in standard refraction seismic surveying. It investigates different techniques for estimation of dispersion characteristics of the interface waves and demonstrates that multi sensor spectral estimation techniques improve the dispersion estimates. The dispersion estimate of the fundamental interface wave mode is used as input to an object function for a model based linearized inversion. The inversion scheme provides an estimate of the shear wave velocity as a function of depth. Three field surveys were performed. Data were acquired with a standard bottom deployed refraction seismic hydrophone array containing 24 or 48 receivers, with a receiver spacing of 2.5 m. Explosive charges were used as sources. The recording time was increased from 0.5 to 8 s, compared to standard refraction seismic ...
A 1,200-W solar AMTEC (alkali metal thermal-to-electric conversion) power system concept was developed and integrated with an advanced global positioning system (GPS) satellite. The critical integration issues for the SAMTEC with the GPS subsystems included (1) packaging within the Delta 2 launch vehicle envelope, (2) deployment and start-up operations for the SAMTEC, (3) SAMTEC operation during all mission phases, (4) satellite field of view restrictions with satellite operations, and (5) effect of the SAMTEC requirements on other satellite subsystems. The SAMTEC power system was compared with a conventional planar solar array/battery power system to assess the differences in system weight, size, and operations. Features of the design include the use of an advanced multitube, vapor anode AMTEC cell design with 24% conversion efficiency, and a direct solar insolation receiver design with integral LiF salt canisters for energy storage to generate power during the ...
A 2009 paper considered possibilities for applying a common display suite to various front-line bubble canopy fighters, whereas further research suggests the cost savings, post Milestone C production/deployment, might not be advantageous. The situation for military cargo and tanker aircraft, may offer a different paradigm. The primary objective of Defense acquisition is to acquire quality products that satisfy user needs with measurable improvements to mission capability and operational support, in a timely manner, and at a fair and reasonable price. DODD 5000.01 specifies that all participants in the acquisition system shall recognize the reality of fiscal constraints, viewing cost as an independent variable. DoD Components must therefore plan programs based on realistic projections of the dollars and manpower likely to be available in future years and also identify the total costs of ownership, as well as the major drivers of total ownership costs. In theory, ...
Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride (BF3)-filled proportional counters, 2) Boron-lined proportional counters, 3) ...
This paper reviews three key initiatives undertaken in the historical city of Oxford to bring about reductions in energy-related CO_2 emissions on a city-wide scale. The author has been part of all the three initiatives. In 2002, a collaborative partnership between academia, industry and city council started the Oxford Solar Initiative (OSI) which uses a community-based approach to help households and organisations in Oxford, financially and technically, to install solar energy systems and energy efficiency measures in buildings. So far OSI has facilitated the installation of 80 active solar systems, over 450 energy efficiency measures and 3,000 low energy bulbs. The scientific basis of OSI is a GIS-based DECoRuM model which estimates and maps baseline energy use and CO_2 emissions on a house-by house level, identifies 'pollution' hotspots, predicts the potential for reductions in CO_2 emissions and monitors reductions achieved as a result of deploying energy ...
We report the results of a prospective clinical study using a new self-expanding nitinol stent (Enterprise) designed for the treatment of wide-necked intracranial aneurysms. We treated 31 saccular, wide-necked intracranial aneurysms in 30 patients. Ten aneurysms had recanalized after prior endovascular treatment without a stent, and 21 aneurysms had not been treated before. Stent deployment was successful in all procedures. Additional coil embolization was performed in all aneurysms. Initial complete angiographic occlusion was achieved in 6 aneurysms, a neck remnant was left in 18 aneurysms and there were 7 residual aneurysms. Angiographic follow-up examinations of 30 lesions after 6 months demonstrated 15 complete occlusions, 8 neck remnants and 7 residual aneurysms. One patient refused the 6-month angiographic follow-up. Spontaneous occlusion of the aneurysm had occurred in 14 patients, and 6 aneurysms showed recanalization. Four of these residual aneurysms were ...