background model performance: Topics by WorldWideScience.org

A refined lack-of-fit statistic to calibrate pesticide fate models for responsive systems

The successful installation of the Europipe 16/11E Riser jacket in July 1994 and the coming installation of Sleipner T jacket in spring 1996 proves that suction installed skirted plate foundations (buckets), may not only be a competitive alternative to piles, but also a complementary foundation solution both for noncohesive and cohesive soils. This paper presents the background for the design analyses of the Europipe 16/11E and Sleipner T foundations in terms of the performed field and model tests, as well as the theoretical models and practical analysis tools utilized for design.

1995-12-01

2

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND: Calibration by inverse modelling was performed with the MACRO transport and fate model using long-term (>10 years) drainflow and isoproturon (IPU) data from western France. Two lack-of-fit (LOF) indices were used to control the inverse modelling: sum of squares (SS) and an alternative statistic called the vertical-horizontal distance integrator (VHDI), which is designed to account for offsets in observed and predicted arrival times of peak IPU concentration. With these data, SS was artificially inflated because it is limited to comparison of predicted and observed IPU concentrations that are concurrent in time. The LOFs were used along with the index of agreement (d) and the correlation coefficient (r) to ascertain the fit of the calibrated models. RESULTS: Predicted arrival ti...

2009-01-01

3

Coal preparation plant condition-based maintenance

Psychological Resilience and Neurocognitive Performance in a Traumatized Community Sample

This report briefly describes the background to colliery engineering maintenance, past experience in machine condition monitoring within coal preparation and the introduction of condition-based maintenance. A role model scheme has been developed for the introduction of condition-based maintenance into coal preparation plants. The report describes the instrumentation and monitoring methods suitable for application to most mineral processing plants, the use of specialist companies to monitor, gather, process and analyse the information and the actions taken by the colliery. Examples of the benefits of operating such a scheme are given in terms of safety, performance and finance. Other problematical aspects of coal processing are examined which have a direct effect on plant condition and availability.

1998-12-31

4

Preclinical Models for Neuroblastoma: Establishing a Baseline for Treatment

BackgroundWhether psychological resilience correlates with neurocognitive performance is largely unknown. Therefore, we assessed association between neurocognitive...Full Text Available

2010-08-01

5

Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions: reliability of a repeated sprint test

BackgroundPreclinical models of pediatric cancers are essential for testing new chemotherapeutic combinations for clinical trials. The most widely used ...Full Text Available

6

BC

Wastenet

Institutional and organizational models ... Review individual centre institutional and organizational models in the light of the tasks to be performed by

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Quantification and deconvolution of asymmetric LC-MS peaks using the bi-Gaussian mixture model and statistical model selection

BackgroundPhysical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However...Full Text Available

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Cavity detection based on EM migration of TEM data; TEM ho data no denji migration ni yoru kudo kenshutsu no kokoromi

BackgroundLiquid chromatography-mass spectrometry (LC-MS) is one of the major techniques for the quantification of metabolites in complex biological samples. Peak modeling is one...Full Text Available

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Aespoe Task Force on modelling of groundwater flow and transport of solutes. Review of Task 6C

With an objective to discuss applicability of resistivity imaging using electromagnetic migration to detection of underground cavity, an applicability test was carried out on calculation of a numerical model and measurement data. By using the numerical model, a calculation was performed on a hypothetical case that a cubic cavity with sides each at 40 m exists in a homogenous medium of 200 ohm-m, with the cavity top located 20 m below the ground surface. As a result, it was possible to structure in a very short calculation time an image of the cavity which cannot be identified by one-dimensional inverse analysis. In the case of this cavity, a center of the image was structured on its lower face. It was shown that a location to indicate the image must be changed according to difference in the measurement locations. In a test on data measured in an underground cavity in the city of Utsunomiya, Tochigi Prefecture, it was found ...

1997-05-27

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Simultaneous Liver-Kidney Versus Liver Transplantation Alone in Patients with End-Stage Liver Disease and Kidney Dysfunction Not on Dialysis

This report forms part of an independent review of the specifications, execution and results of Task 6 of the Aespoe Task Force on Modelling of Groundwater Flow and Transport of Solutes, which is seeking to provide a bridge between site characterization (SC) and performance assessment (PA) approaches to solute transport in fractured rock. The present report is concerned solely with Task 6C, which relates to the construction and parametrisation of a block-scale hydrostructural model of the TRUE Block Scale region of the Aespoe Hard Rock laboratory. The task objectives, specifications and outcome are summarised and reviewed. Also, consideration is given to how the hydrostructural model might affect the outcomes of Task 6D and 6E. The main conclusions of this review are summarised below: The Task 6C hydrostructural model is a more comprehensive approach to quantitatively describing a ...

2005-03-01

11

British Library Electronic Table of Contents (United Kingdom)

BackgroundSince implementation of the Model for End-stage Liver Disease (MELD), the number of simultaneous liver-kidney transplantations (SLKT) has increased in the United States. However, predictors and survival benefit of SLKT compared to liver transplantation alone (LTA) are not well defined. MethodsOrgan Procurement and Transplantation Network data of patients with end-stage liver disease (ESLD) with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 who had not been on dialysis while on the waiting list and underwent liver transplantation between 2002 and 2008 were analyzed. To identify predictors of undergoing SLKT versus LTA, multiple logistic regression analysis was performed. Cox proportional hazards regression analysis was used to assess the association between...

2011-01-01

12

Causes of denting. Volume 1. Summary report. Final report

Variations of endonasal anatomy: relevance for the endoscopic endonasal transsphenoidal approach

This summary report outlines the work that was performed to gain a more complete understanding of denting corrosion of steam generators in PWRs. Background laboratory and plant data on denting were compiled, reviewed and correlated to determine how various exposure conditions affect denting. Two high-temperature chemistry analytical models were reviewed and evaluated by experimental simulation of impurity concentration in the heat transfer and isothermal capsule tests. Simulation of impurity concentration for three cooling waters (lake, river, and cooling tower) was evaluated. The effects of species concentration (Cu/sup + +/, Cl/sup -/, O/sub 2/, and H/sup +/), contaminant thresholds (established by isothermal and heat transfer tests), and heat flux as indicated by superheat on denting were examined. A discussion of several pertinent observations and conclusions drawn from these tasks (as they pertain to plant operation) ...

1984-05-01

13

Edge filter and fringe imaging for laser Doppler wind speed measurement

BackgroundThe endoscopic endonasal transsphenoidal approach (EETA) to the pituitary is performed by ear, nose, and throat (ENT) surgeons in collaboration with neurosurgeons but also...Full Text Available

2010-06-01

14

Time-dependent ARMA modeling of genomic sequences

Optical measurement of the Doppler shift of laser backscatter, using a near-IR, visible, or ultraviolet laser, is potentially more robust and field reliable than coherent, heterodyne measurement with an IR laser. The direct measurement of the displacement of Fabry-Perot interference fringes is possible, but entails expensive, technically challenging, imaging detectors. The 'edge technique' permits Doppler shift measurements with relatively simple detectors and detector electronics, and has been implemented with Fabry-Perot etalons and with atomic line filters. Simple analytical models of the fringe imaging and edge detection techniques are presented, permitting ready calculation of the potential performance of either, for various atmospheric conditions and for various lidar hardware configurations. The predictions of the analytical models are confirmed by computer models, which in turn allow more ...

1997-08-01

15

Progression of liver cirrhosis to HCC: an application of hidden Markov model

BackgroundOver the past decade, many investigators have used sophisticated time series tools for the analysis of genomic sequences. Specifically, the correlation of the nucleotide...Full Text Available

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Predation and fragmentation portrayed in the statistical structure of prey time series

BackgroundHealth service databases of administrative type can be a useful tool for the study of progression of a disease, but the data reported in such sources could be affected...Full Text Available

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Enzymatic engineering of the porcine genome with transposons and recombinases

BackgroundStatistical autoregressive analyses of direct and delayed density dependence are widespread in ecological research. The models suggest that changes in ecological factors...Full Text Available

18

Embryonic Senescence and Laminopathies in a Progeroid Zebrafish Model

BackgroundSwine is an important agricultural commodity and biomedical model. Manipulation of the pig genome provides opportunity to improve production efficiency, enhance disease...Full Text Available

19

A mathematical model of mitochondrial swelling

BackgroundMutations that disrupt the conversion of prelamin A to mature lamin A cause the rare genetic disorder Hutchinson-Gilford progeria syndrome and a group of laminopathies....Full Text Available

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A mathematical model of bone remodeling dynamics for normal bone cell populations and myeloma bone disease

BackgroundThe permeabilization of mitochondrial membranes is a decisive event in apoptosis or necrosis culminating in cell death. One fundamental mechanism by which...Full Text Available

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Phase transition in a simple plasma model

BackgroundMultiple myeloma is a hematologic malignancy associated with the development of a destructive osteolytic bone disease.ResultsMathematical...Full Text Available

22

Weibel and Two-Stream Instabilities for Intense Charged Particle Beam Propagation through Neutralizing Background Plasma

A phase transition of gas-liquid type with an upper critical point is examined which arises in a model of charges of one sign on compensating background (OCP). The phase transition parameters are dependent on the detailed assumptions about the compressibility of the background, but the occurrence of this transition is independent on the background equation of state. In the electron-gas model ('jellium'), this transition appears to rule out Wigner crystallization. A variational principle in statistical mechanics is used to derive so-called Double-OCP model for a superposition of two one-component plasma models for charges of opposite sign. The free energy of this model sets an upper bound to that of a real plasma. Situations are discussed where this transition should manifest itself in anomalies in the approximate ...

2009-01-01

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On the performances of Intensity Modulated Protons, RapidArc and Helical Tomotherapy for selected paediatric cases

Properties of the multi-species electromagnetic Weibel and electrostatic two-stream instabilities are investigated for an intense ion beam propagating through background plasma. Assuming that the background plasma electrons provide complete charge and current neutralization, detailed linear stability properties are calculated within the framework of a macroscopic cold-fluid model for a wide range of system parameters.

2004-04-09

24

Comprehensive Analysis of Blood Culture Performed at Nine University Hospitals in Korea

BackgroundTo evaluate the performance of three different advanced treatment techniques on a group of complex paediatric cancer cases.MethodsCT...Full Text Available

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Cognitive performance in relapsing remitting multiple sclerosis: A longitudinal study in daily practice using a brief computerized cognitive battery

BackgroundOptimal blood culture performance is critical for successful diagnosis and treatment of sepsis. To understand the status of blood culture, we investigated several aspects...Full Text Available

2011-04-01

26

SNAP sky background at the north ecliptic pole

BackgroundThere is need for a cognitive test battery that can be easily used in clinical practice to detect or monitor cognitive performance in patients with multiple sclerosis (MS)....Full Text Available

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The search for stable prognostic models in multiple imputed data sets

I summarize the extant direct and indirect data on the sky background SNAP will see at the North Ecliptic Pole over the wavelength range 0.4 < {lambda} < 1.7 {micro}m. At the spatial resolution of SNAP the sky background due to stars and galaxies is resolved, so the only source considered is zodiacal light. Several models are explored to provide interpolation in wavelength between the broadband data from HST and COBE observations. I believe the input data are now established well enough that the accuracy of the sky background presented here is sufficient for SNAP simulations, and that it will stand up to scrutiny by reviewers.

2002-07-01

28

Pathophysiological, Genetic and Gene Expression Features of a Novel Rodent Model of the Cardio-Metabolic Syndrome

BackgroundIn prognostic studies model instability and missing data can be troubling factors. Proposed methods for handling these situations are bootstrapping (B) and Multiple imputation...Full Text Available

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Modeling RNA polymerase competition: the effect of ?-subunit knockout and heat shock on gene transcription level

BackgroundComplex etiology and pathogenesis of pathophysiological components of the cardio-metabolic syndrome have been demonstrated in humans and animal models.Methodology/Principal...Full Text Available

30

Combustible Cartridge Cases: Current Status and Future Prospects.

BackgroundModeling of a complex biological process can explain the results of experimental studies and help predict its characteristics. Among such processes is transcription in...Full Text Available

31

Volume - Rotorcraft Bibliography

The state of the art of our understanding of combustible cartridge cases is presented. The report, after a background section, discusses the models that exist today and presents new models of combustible cartridge case burning. Following a summary of expe...

1992-01-01

32

Multiple Network-on-Chip Model for High Performance Neural Network

Ormiston, R.A., Applications of the Induced Power Model and Performance of Conventional and Advanced Rotorcraft, 2010, details ...

33

KoreaScience (Korea)

Full Text Available

2010-03-01

34

High-Performance SPICE Development Including an Analytical Transient Photocurrent BJT Model

No abstract prepared.

2000-08-01

35

Screening Criteria for Loss of Room Cooling Failure

Complete calculations of the accelerator related background in the muon spectrometer of the CMS detector at the Large Hadron Collider are presented. The simulations have been performed with the STRUCT multi-turn tracking code and the MARS and FLUKA cascade codes taking into account latest information of the LHC lattice, vacuum conditions, beam cleaning system and the shielding and layout of the CMS experiment. Beam loss distributions in the interaction regions and their vicinities and their contribution to the background levels in the muon spectrometer of CMS are analyzed. The studies show that hadronic and electromagnetic components of machine background are efficiently suppressed by the proposed CMS shielding. High energy muons penetrate through the shielding, but in positions of significance they do not contribute more than a few percent compared to the background generated by ...

36

Do we really need a central governor to explain brain regulation of exercise performance?

In this report, we estimated the temperature of the pump rooms and reviewed the operability of the components under the loss of the HVAC (Heating, Ventilation, and Air Condition) system. The issues relevant to the HVAC system in the PSA (Probabilistic Safety Assessment) FT (Fault Tree) model are as follows: (1) Does the loss of the HVAC system bring about a function failure of other components? (2) Can the operator take action to reduce the temperature of the room in case of a HVAC function failure? At present, we do not know whether a component will lose its function or not under the loss of the HVAC. ASME Standard describes that a recovery action can be credited if the related recovery action is included in the procedure or there are similar recovery experiences in the plant. However, there is no description about the recovery action of the HVAC in the EOP (Emergency Operation Procedure) of the UCN3, 4 under the situation of a loss of the HVAC. Even though we ...

2007-01-15

37

The ANL electric vehicle battery R&D program for DOE-EHP. Quarterly progress report, October--December 1990

In this paper two different models of brain regulation of exercise performance are critically compared: the central governor model proposed by Noakes and colleagues, and an alternative psycholobiological model based on motivational intensity theory. PMID:18618133

2008-07-10

38

The ANL electric vehicle battery R&D program for DOE-EHP. Progress report, October 1991--March 1992

The Electrochemical Technology Program at Argonne National Laboratory (ANL) provides technical and programmatic support to DOE`s Electric and Hybrid Propulsion Division (DOE-EBP). The goal of DOE-EHP is to advance promising EV propulsion technologies to levels where industry will continue their commercial development and thereby significantly reduce petroleum consumption in the transportation sector of the US economy. In support of this goal, ANL provides research, development, testing/evaluation, post-test analysis, modeling, database management, and technical management of industrial R&D contracts on advanced battery and fuel cell technologies for DOE-EBP. This report summarizes the objectives, background, technical progress, and status of ANL electric vehicle battery R&D tasks for DOE-EHP during the period of October 1, 1990 through December 31, 1990. The work is organized into the following six task areas: 1.0 Project Management; ...

1990-12-31

39

The ANL electric vehicle battery R D program for DOE-EHP

The Electrochemical Program at Argonne National Laboratory (ANL) provides technical and programmatic support to DOE`s Electric and Hybrid Propulsion Division (DOE-EHP). The goal of DOE-EHP is to advance promising electric-vehicle (EV) propulsion technologies to levels where industry will continue their commercial development and thereby. significantly reduce petroleum consumption in the transportation sector of the economy. In support of this goal, ANL provides research, development, testing/evaluation, post-test analysis, modeling, database management, and technical management of industrial R&D contracts on advanced battery and fuel cell technologies for DOE-EHP. This report summarizes the battery-related activities undertaken during the period of October 1, 1991 through March 31, 1992. In this report, the objective, background, technical progress, and status are described for each task. These tasks are structured into the following task ...

1992-12-31

40

The ANL electric vehicle battery R D program for DOE-EHP

The Electrochemical Technology Program at Argonne National Laboratory (ANL) provides technical and programmatic support to DOE's Electric and Hybrid Propulsion Division (DOE-EBP). The goal of DOE-EHP is to advance promising EV propulsion technologies to levels where industry will continue their commercial development and thereby significantly reduce petroleum consumption in the transportation sector of the US economy. In support of this goal, ANL provides research, development, testing/evaluation, post-test analysis, modeling, database management, and technical management of industrial R D contracts on advanced battery and fuel cell technologies for DOE-EBP. This report summarizes the objectives, background, technical progress, and status of ANL electric vehicle battery R D tasks for DOE-EHP during the period of October 1, 1990 through December 31, 1990. The work is organized into the following six task areas: 1.0 Project Management; ...

1990-01-01

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41

The ANL Electrichemical Program for DOE on electric vehicle R&D. Progress report, July--September 1992

The Electrochemical Program at Argonne National Laboratory (ANL) provides technical and programmatic support to DOE's Electric and Hybrid Propulsion Division (DOE-EHP). The goal of DOE-EHP is to advance promising electric-vehicle (EV) propulsion technologies to levels where industry will continue their commercial development and thereby. significantly reduce petroleum consumption in the transportation sector of the economy. In support of this goal, ANL provides research, development, testing/evaluation, post-test analysis, modeling, database management, and technical management of industrial R D contracts on advanced battery and fuel cell technologies for DOE-EHP. This report summarizes the battery-related activities undertaken during the period of October 1, 1991 through March 31, 1992. In this report, the objective, background, technical progress, and status are described for each task. These tasks are structured into the following ...

1992-01-01

42

The ANL Electrichemical Program for DOE on electric vehicle R D

The Electrochemical Technology Program at Argonne National Laboratory (ANL) provides technical and programmatic support to DOE`s Electric and Hybrid Propulsion Division (DOE-EHP). The goal of DOE-EHP is to advance promising electric-vehicle (EV) propulsion technologies to levels where industry will continue their commercial development and thereby significantly reduce petroleum consumption in the transportation sector of the economy. In support of this goal, ANL provides research, development, testing/evaluation, post-test analysis, modeling, database management, and technical management of industrial R&D contracts on advanced battery technologies for DOE-EHP. This report summarizes the battery-related activities undertaken during the period of July 1, 1992 through September 30, 1992. In this report, the objective, background, technical progress, and status are described for each task. The work is organized into the following task areas: ...

1992-12-31

43

Structural transition metal chemistry

The Electrochemical Technology Program at Argonne National Laboratory (ANL) provides technical and programmatic support to DOE's Electric and Hybrid Propulsion Division (DOE-EHP). The goal of DOE-EHP is to advance promising electric-vehicle (EV) propulsion technologies to levels where industry will continue their commercial development and thereby significantly reduce petroleum consumption in the transportation sector of the economy. In support of this goal, ANL provides research, development, testing/evaluation, post-test analysis, modeling, database management, and technical management of industrial R D contracts on advanced battery technologies for DOE-EHP. This report summarizes the battery-related activities undertaken during the period of July 1, 1992 through September 30, 1992. In this report, the objective, background, technical progress, and status are described for each task. The work is organized into the following task ...

1992-01-01

44

ANL`s electric vehicle battery activities for USABC. Progress report, April--September 1992

This thesis is divided up into five chapters as outlined below. Chapter 1 gives the background to the techniques used in this thesis including X-ray structure determination and ab initio methods. An overview of some recent studies using ab initio methods to study transition metal complexes is also given. Chapter 2 investigates structural trans influence in a number of transition metal and p-block complexes. The database and ab initio studies showed that the classical trans influence model based on Pt(II) chemistry does not always hold. For some systems (eg. d sup 1 sup 0 s sup 0 for Sb sup V and Sn sup I sup V) the cis influence is of similar magnitude to the trans influence. For other systems (d sup 0), the trans influence is not as powerful as usually assumed. Chapter 3 is an investigation into the bridging chloride unit. A database study was performed on three systems (M-CI-M', M-CI...H and M-CI...Li/Na/K). Reaction ...

2002-01-01

45

ANL's electric vehicle battery activities for USABC. [US Advanced Battery Consortium (USABC)

The Electrochemical Technology Program at Argonne National Laboratory (ANL) provides advanced battery R&D; technology transfer to industry; technical analyses, assessments, modeling, and databases; and independent testing and post-test analyses of advanced batteries. These capabilities and services are being offered to the US Advanced Battery Consortium (USABC) and Cooperative Research and Development Agreements (CRADA) are being negotiated for USABC-sponsored work at ANL. A small portion of DOE`s cost share for USABC projects has been provided to ANL to continue R&D and testing activities on key technologies that were previously supported directly by DOE. This report summarizes progress on these USABC projects during the period of April I through September 30, 1992. In this report, the objective, background, technical progress, and status are described for each task. The work is organized into the following task areas: 1.0 ...

1992-12-31

46

The CORONIS Trial. International study of caesarean section surgical techniques: a randomised fractional, factorial trial

The Electrochemical Technology Program at Argonne National Laboratory (ANL) provides advanced battery R D; technology transfer to industry; technical analyses, assessments, modeling, and databases; and independent testing and post-test analyses of advanced batteries. These capabilities and services are being offered to the US Advanced Battery Consortium (USABC) and Cooperative Research and Development Agreements (CRADA) are being negotiated for USABC-sponsored work at ANL. A small portion of DOE's cost share for USABC projects has been provided to ANL to continue R D and testing activities on key technologies that were previously supported directly by DOE. This report summarizes progress on these USABC projects during the period of April I through September 30, 1992. In this report, the objective, background, technical progress, and status are described for each task. The work is organized into the following task areas: 1.0 ...

1992-01-01

47

Support for stroke patients in resumption of driving: patient survey and driving simulator trial

BackgroundCaesarean section is one of the most commonly performed operations on women throughout the world. Rates have increased in recent years – about 20–25% in...Full Text Available

48

Performance and usefulness of the Hexagon rapid diagnostic test in children with asymptomatic malaria living in the Mount Cameroon region

Background:Encouragement of stroke patients to resume driving is important to promote their reintegration into the community. Limited rehabilitation has been performed in this regard,...Full Text Available

49

Performance and Consistency of Indicator Groups in Two Biodiversity Hotspots

BackgroundRapid and correct diagnosis of malaria is considered an important strategy in the control of the disease. However, it remains to be determined how well these tests can...Full Text Available

50

Nostril dominance at rest associated with performance of a left hemisphere-specific cancellation task

BackgroundIn a world limited by data availability and limited funds for conservation, scientists and practitioners must use indicator groups to define spatial conservation priorities....Full Text Available

51

Intra-Individual Variability in Alzheimer's Disease and Cognitive Aging: Definitions, Context, and Effect Sizes

Background:An association has been reported between the dominant nostril through which we breathe and the cerebral hemisphere found to be active.Aims:To...Full Text Available

2008-07-01

52

Elastic stable intramedullary nailing of midclavicular fractures in athletes

Background/AimsTo explore different definitions of intra-individual variability (IIV) to summarize performance on commonly utilized cognitive tests (Mini Mental State Exam; Clock...Full Text Available

53

Developing a Performance Measurement Framework and Indicators for Community Health Service Facilities in Urban China

Background: Intramedullary fixation of midclavicular fractures may be a better option than non-operative treatment for high performance/professional athletes because of the potential reduction...Full Text Available

2003-12-01

54

Convective burn from use of hairdryer for heel warming prior to the heel prick test - a case report

BackgroundChina has had no effective and systematic information system to provide guidance for strengthening PHC (Primary Health Care) or account to citizens on progress. We report...Full Text Available

55

Comparative genomics reveals 104 candidate structured RNAs from bacteria, archaea, and their metagenomes

BackgroundBlood sampling through heel lancing is the most common invasive painful procedure performed on newborn infants.Case PresentationWe report...Full Text Available

56

Bioaccumulation and toxicity of selenium compounds in the green alga Scenedesmus quadricauda

BackgroundStructured noncoding RNAs perform many functions that are essential for protein synthesis, RNA processing, and gene regulation. Structured RNAs can be detected by comparative...Full Text Available

2010-01-01

57

A boosting method for maximizing the partial area under the ROC curve

BackgroundSelenium is a trace element performing important biological functions in many organisms including humans. It usually affects organisms in a strictly dosage-dependent manner...Full Text Available

58

Assimilating remote sensing and in situ observations into a coastal model of northern South China Sea using ensemble Kalman filter

BackgroundThe receiver operating characteristic (ROC) curve is a fundamental tool to assess the discriminant performance for not only a single marker but also a score function combining...Full Text Available

59

British Library Electronic Table of Contents (United Kingdom)

Major forecast errors on the background error covariance from initial conditions, atmospheric forcing, model open boundary conditions, and the river discharges are examined in a coastal model of northern South China Sea. The analysis of background error covariance matrix produced by model ensemble shows that the perturbations of the initial conditions and atmospheric forcing play major roles in producing and maintaining the amplitude of ensemble spread except for the sea surface height (SSH) field. The perturbation of model open boundary conditions can influence ensemble spread of all variables and covariance between temperature and velocity or between temperature and SSH. The perturbation of river discharge mainly affects the covariance of salinity in river estuary. A data assimilation ex...

2011-01-01

60

A Cross-Model Comparison of Human Performance Modeling Tools ...

Nevada Test Site, 2006 Waste Management Monitoring Report, Area 3 and Area 5 Radioactive Waste Management Sites

Scheduling is a stochastic process performed by production rules. In .... activated, which causes the available goal queue size to be exceeded, then the first goal to ...... when in doubt turn toward the terminal or when in doubt go ...

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Wavelet-based Gaussian-mixture hidden Markov model for the detection of multistage seizure dynamics: A proof-of-concept study

Environmental monitoring data were collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) at the Nevada Test Site. These data are associated with radiation exposure, air, groundwater, meteorology, vadose zone, subsidence, and biota. This report summarizes the 2006 environmental data to provide an overall evaluation of RWMS performance and to support environmental compliance and performance assessment (PA) activities. Some of these data (e.g., radiation exposure, air, and groundwater) are presented in other reports (U.S. Department of Energy, 2006; Warren and Grossman, 2007; National Security Technologies, LLC, 2007). Direct radiation monitoring data indicate that exposure levels around the RWMSs are at or below background levels. Air monitoring data at the Area 3 and Area 5 RWMSs indicate that tritium concentrations are slightly above background levels. There is no ...

2007-06-30

62

Transcriptional profile of isoproterenol-induced cardiomyopathy and comparison to exercise-induced cardiac hypertrophy and human cardiac failure

BackgroundEpilepsy is a common neurological disorder characterized by recurrent electrophysiological activities, known as seizures. Without the appropriate detection strategies,...Full Text Available

63

The endogenous hydrogen sulfide producing enzyme cystathionine-? synthase contributes to visceral hypersensitivity in a rat model of irritable bowel syndrome

BackgroundIsoproterenol-induced cardiac hypertrophy in mice has been used in a number of studies to model human cardiac disease. In this study, we compared the transcriptional response...Full Text Available

64

The European sea bass Dicentrarchus labrax genome puzzle: comparative BAC-mapping and low coverage shotgun sequencing

BackgroundThe pathogenesis of visceral hypersensitivity, a characteristic pathophysiological feature of irritable bowel syndrome (IBS), remains elusive. Recent studies suggest a...Full Text Available

65

Research and development of a new RF-assisted device for bloodless rapid transection of the liver: Computational modeling and in vivo experiments

BackgroundFood supply from the ocean is constrained by the shortage of domesticated and selected fish. Development of genomic models of economically important fishes should assist...Full Text Available

66

Redistribution of pulmonary blood flow impacts thermodilution-based extravascular lung water measurements in a model of acute lung injury

BackgroundEfficient and safe transection of biological tissue in liver surgery is strongly dependent on the ability to address both parenchymal division and hemostasis simultaneously....Full Text Available

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Reconsidering the use of rankings in the valuation of health states: a model for estimating cardinal values from ordinal data

BackgroundStudies using transthoracic thermodilution have demonstrated increased extravascular lung water (EVLW) measurements attributed to progression of edema and...Full Text Available

2009-11-01

68

Paracetamol reduces influenza-induced immunopathology in a mouse model of infection without compromising virus clearance or the generation of protective immunity

BackgroundIn survey studies on health-state valuations, ordinal ranking exercises often are used as precursors to other elicitation methods such as the time trade-off (TTO) or standard...Full Text Available

69

On the ease of predicting the thermodynamic properties of beta-cyclodextrin inclusion complexes

BackgroundSeasonal influenza A infection affects a significant cohort of the global population annually, resulting in considerable morbidity and mortality. Therapeutic strategies...Full Text Available

2011-05-01

70

Non-Invasive Stem Cell Therapy in a Rat Model for Retinal Degeneration and Vascular Pathology

BackgroundIn this study we investigated the predictability of three thermodynamic quantities related to complex formation. As a model system we chose the host-guest complexes of...Full Text Available

71

Mouse model predicts effects of smoking and varenicline on event-related potentials in humans

BackgroundRetinitis pigmentosa (RP) is characterized by progressive night blindness, visual field loss, altered vascular permeability and loss of central vision. Currently there...Full Text Available

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Molecular conservation of estrogen-response associated with cell cycle regulation, hormonal carcinogenesis and cancer in zebrafish and human cancer cell lines

Background:Nicotine alters auditory event-related potentials (ERPs) in rodents and humans and is an effective treatment for smoking cessation. Less is known about the effects of...Full Text Available

2010-06-01

73

Lack of LDL Receptor Enhances Amyloid Deposition and Decreases Glial Response in an Alzheimer's Disease Mouse Model

BackgroundThe zebrafish is recognized as a versatile cancer and drug screening model. However, it is not known whether the estrogen-responsive genes and signaling pathways that are...Full Text Available

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Is the Kaiser Permanente model superior in terms of clinical integration?: a comparative study of Kaiser Permanente, Northern California and the Danish healthcare system

BackgroundApolipoprotein E (ApoE), a cholesterol carrier associated with atherosclerosis, is a major risk factor for Alzheimer's disease (AD). The low-density lipoprotein receptor...Full Text Available

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Inhibition of HIV-1 Infection in Ex Vivo Cervical Tissue Model of Human Vagina by Palmitic Acid; Implications for a Microbicide Development

BackgroundIntegration of medical care across clinicians and settings could enhance the quality of care for patients. To date, there is limited data on the levels of integration in...Full Text Available

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In silico modeling of the specific inhibitory potential of thiophene-2,3-dihydro-1,5-benzothiazepine against BChE in the formation of ?-amyloid plaques associated with Alzheimer's disease

BackgroundApproximately 80% of all new HIV-1 infections are acquired through sexual contact. Currently, there is no clinically approved microbicide, indicating a clear and...Full Text Available

77

Identification and In Vivo Characterization of NvFP-7R, a Developmentally Regulated Red Fluorescent Protein of Nematostella vectensis

BackgroundAlzheimer's disease, known to be associated with the gradual loss of memory, is characterized by low concentration of acetylcholine in the hippocampus and cortex part of...Full Text Available

78

ICC-MY coordinate smooth muscle electrical and mechanical activity in the murine small intestine

BackgroundIn recent years, the sea anemone Nematostella vectensis has emerged as a critical model organism for comparative genomics and developmental biology. Although...Full Text Available

79

BackgroundAnimals carrying genetic mutations have provided powerful insights into the role of interstitial cells of Cajal (ICC) in motility. One classic model is...Full Text Available

2010-05-01

80

Formal reasoning on qualitative models of coinfection of HIV and Tuberculosis and HAART therapy

BackgroundDue to the high morbidity and mortality of fulminant hepatitis, early diagnosis followed by early effective treatment is the key for prognosis improvement. So far, little...Full Text Available

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81

Extracellular Administration of BCL2 Protein Reduces Apoptosis and Improves Survival in a Murine Model of Sepsis

BackgroundSeveral diseases, many of which nowadays pandemic, consist of multifactorial pathologies. Paradigmatic examples come from the immune response to pathogens, in which cases...Full Text Available

82

Expression Signatures of Metastatic Capacity in a Genetic Mouse Model of Lung Adenocarcinoma

BackgroundSevere sepsis and septic shock are major causes of morbidity and mortality worldwide. In experimental sepsis there is prominent apoptosis of various cell types, and genetic...Full Text Available

83

Exploring nervous system transcriptomes during embryogenesis and metamorphosis in Xenopus tropicalis using EST analysis

BackgroundNon-small cell lung cancer (NSCLC) is the foremost cause of cancer-related death in Western countries, which is due partly to the propensity of NSCLC cells to metastasize....Full Text Available

84

Evaluating professionalism in medical undergraduates using selected response questions: findings from an item response modelling study

BackgroundThe western African clawed frog Xenopus tropicalis is an anuran amphibian species now used as model in vertebrate comparative genomics. It provides the...Full Text Available

85

Effects of removal of dietary polyunsaturated fatty acids on plasma extravasation and mechanical allodynia in a trigeminal neuropathic pain model

BackgroundProfessionalism is a difficult construct to define in medical students but aspects of this concept may be important in predicting the risk of postgraduate misconduct. For...Full Text Available

86

Djinn Lite: a tool for customised gene transcript modelling, annotation-data enrichment and exploration

BackgroundNeuropathic pain (NP) is partially mediated by neuroinflammatory mechanisms, and also modulates local neurogenic inflammation. Dietary lipids, in particular the total amount...Full Text Available

87

Differential Regulation of PDE5 Expression in Left and Right Ventricles of Feline Hypertrophy Models

BackgroundThere is an ever increasing rate of data made available on genetic variation, transcriptomes and proteomes. Similarly, a growing variety of bioinformatic programs are becoming...Full Text Available

88

Determinants of health insurance ownership among South African women

BackgroundThough long known to affect smooth muscle biology, recent studies indicate that phosphodiesterase 5 (PDE5) is also expressed in myocardium. Recognizing that the regulation...Full Text Available

89

Cross-sectional measures and modelled estimates of blood alcohol levels in UK nightlife and their relationships with drinking behaviours and observed signs of inebriation

BackgroundStudies conducted in developed countries using economic models show that individual- and household- level variables are important determinants of health insurance ownership....Full Text Available

90

Computational simulation of vasopressin secretion using a rat model of the water and electrolyte homeostasis

BackgroundManagement of nightlife in UK cities focuses on creating safe places for individuals to drink. Little is known about intoxication levels as measuring total alcohol consumption...Full Text Available

91

Comparative optimism in models involving both classical clinical and gene expression information

BackgroundIn mammals, vasopressin (AVP) is released from magnocellular neurons of the hypothalamus when osmotic pressure exceeds a fixed set-point. AVP participates to the hydromineral...Full Text Available

92

Brachytherapy of stage II mobile tongue carcinoma. Prediction of local control and QOL

BackgroundIn cancer research, most clinical variables have already been investigated and are now well established. The use of transcriptomic variables has raised two problems: restricting...Full Text Available

93

Application of the PM6 semi-empirical method to modeling proteins enhances docking accuracy of AutoDock

BackgroundThere is no consensus as to the prognostic model for brachytherapy of tongue carcinoma. This study was designed to evaluate the prognostic factors for local control based...Full Text Available

94

Apolipoprotein E-Mimetics Inhibit Neurodegeneration and Restore Cognitive Functions in a Transgenic Drosophila Model of Alzheimer's Disease

BackgroundMolecular docking methods are commonly used for predicting binding modes and energies of ligands to proteins. For accurate complex geometry and binding energy estimation,...Full Text Available

95

Actinobacillus actinomycetemcomitans Lipopolysaccharide-Mediated Experimental Bone Loss Model for Aggressive Periodontitis

BackgroundMutations of the amyloid precursor protein gene (APP) are found in familial forms of Alzheimer's disease (AD) and some lead to the elevated production...Full Text Available

96

AICAR inhibits adipocyte differentiation in 3T3L1 and restores metabolic alterations in diet-induced obesity mice model

BackgroundBacterial constituents, such as Gram-negative derived lipopolysaccharide (LPS), can initiate inflammatory bone loss through induction of host-derived inflammatory...Full Text Available

2007-03-01

97

A predictive model of Health Related Quality of life of parents of chronically ill children: the importance of care-dependency of their child and their support system

BackgroundObesity is one of the principal causative factors involved in the development of metabolic syndrome. AMP-activated protein kinase (AMPK) is an energy sensor that regulates...Full Text Available

98

A Patient Survey Assessing the Awareness and Acceptability of the Emergency Care Summary and Its Consent Model in Scotland

BackgroundParents of chronically ill children are at risk for a lower Health Related Quality of Life (HRQoL). Insight in the dynamics of factors influencing parental HRQoL is necessary...Full Text Available

99

A Novel Mouse Model of Red Blood Cell Storage and Post-Transfusion in Vivo Survival

BackgroundThe Emergency Care Summary (ECS) was introduced in 2006 to allow aspects of the general practitioner (GP; family doctor, equivalent to primary care physician) medical record...Full Text Available

100

Enhanced Core Noise Modeling for Turbofan Engines

BackgroundStorage of RBCs is necessary for an adequate blood supply. However, reports have identified potential negative sequelae of transfusing stored RBCs. An animal...Full Text Available

2009-08-01

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101

Uncertainty analysis for low-level radioactive waste disposal performance assessment at Oak Ridge National Laboratory

This report describes work performed by MTC Technologies (MTCT) for NASA Glenn Research Center (GRC)

2011-01-01

102

Search for supersymmetry in 2 different topologies with the L3 detector at Lep; Recherche de supersymetrie dans les canaux avec un ou deux leptons avec le detecteur L3 a LEP

A performance assessment of the operating Solid Waste Storage Area 6 (SWSA 6) facility for the disposal of low-level radioactive waste at the Oak Ridge National Laboratory has been prepared to provide the technical basis for demonstrating compliance with the performance objectives of DOE Order 5820.2A, Chapter 111.2 An analysis of the uncertainty incorporated into the assessment was performed which addressed the quantitative uncertainty in the data used by the models, the subjective uncertainty associated with the models used for assessing performance of the disposal facility and site, and the uncertainty in the models used for estimating dose and human exposure. The results of the uncertainty analysis were used to interpret results and to formulate conclusions about the performance assessment. This paper discusses the ...

1994-12-31

103

Influence of sedation and data acquisition method on tracer uptake in animal models: ["1"2"3I]-2-iodo-L-phenylalanine in pentobarbital-sedated tumor-bearing athymic mice

The present thesis presents two different aspects of my work in the L3 experiment, which are on one side the search for supersymmetric particles, the scalar leptons, in two different topologies 'electron + X + E' and '2 leptons + 2 photons + E', each of them being related to two theoretical SUSY models, m-SUGRA and GMSB. On the other side my work has been completed by the study of the BGO crystal electromagnetic calorimeter of L3, and the calibration of the electromagnetic calorimeter EGAP. After the essential motivations being reviewed, the production and disintegration modes are detailed concerning the scalar lepton sector at LEP. Then one presents the analysis techniques which I used to perform my selection, and also the results obtained from the data collected by L3 for center of mass energies between {radical} S =183 GeV and 202 GeV. The selection criteria that allow to isolate the events I looked for, ...

2000-11-13

104

Higgs, SUSY and the standard model at {gamma}{gamma} colliders

Objectives: To minimize movement artifacts during tracer imaging studies, the animals are generally sedated. Although many reports describe the effect of barbiturates on brain function, less is published about the general impact on the extracerebral metabolism and tracer biodistribution. This report describes the influence of pentobarbital on tumor uptake of ["1"2"3I]-2-iodo-L-phenylalanine (["1"2"3I]-2I-L-PA) using dissection and nuclear imaging. Methods: R1M tumor-bearing athymic mice were divided into two populations: untreated and pentobarbital-treated. Each group was subjected to dynamic and static planar imaging and organ dissection after ["1"2"3I]-2I-L-PA injection. Two-compartment blood modeling was performed. Analysis of variance (ANOVA), t test and clustered boxplot analyses were used to compare the results between the treatment groups and between the data acquisition methods. Results: Two-compartment blood ...

2006-01-01

105

Higgs, SUSY and the standard model at #gamma##gamma# colliders

In this report, I surveyed physics potential of the {gamma}{gamma} option of a linear e{sup +}e{sup -} collider with the following questions in mind: What new discovery can be expected at a {gamma}{gamma} collider in addition to what will be learned at its 'parent' e{sup +}e{sup -} linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e{sup -} beams, we find that a {gamma}{gamma} collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e{sup -}e{sup -} system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a {gamma}{gamma} collider. CP property of the scalar sector can be explored in detail by making use of linear polarization ...

2001-10-11

106

BPS Condensates, Matrix Models and Emergent String Theory

In this report, I surveyed physics potential of the #gamma##gamma# option of a linear e"+e"- collider with the following questions in mind: What new discovery can be expected at a #gamma##gamma# collider in addition to what will be learned at its 'parent' e"+e"- linear collider? By taking account of the hard energy spectrum and polarization of colliding photons, produced by Compton back-scattering of laser light off incoming e"- beams, we find that a #gamma##gamma# collider is most powerful when new physics appears in the neutral spin-zero channel at an invariant mass below about 80% of the c.m. energy of the colliding e"-e"- system. If a light Higgs boson exists, its properties can be studied in detail, and if its heavier partners or a heavy Higgs boson exists in the above mass range, they may be discovered at a #gamma##gamma# collider. CP property of the scalar sector can be explored in detail by making use of linear polarization of the colliding photons, decay angular correlations ...

2001-10-11

107

Performance of the Electric power companies of Burkina Faso, the Ivory Coast, Mali and Senegal, and their organizational models

A prescription is given for computing anomalous dimensions of single trace operators in SYM at strong coupling and large $N$ using a reduced model of matrix quantum mechanics. The method involves treating some parts of the operators as "BPS condensates" which, in certain limit, have a dual description as null geodesics on the $S^5$. In the gauge theory, the condensate is similar to a representative of the chiral ring and it is described by a background of commuting matrices. Excitations around these condensates correspond to excitations around this background and take the form of ``string bits" which are dual to the "giant magnons" of Hofman and Maldacena. In fact, the matrix model approach gives a {\\it quantum} description of these string configurations and explains why the infinite momentum limit suppresses the quantum effects. This method allows, not only to derive part of the classical sigma ...

2007-01-01

108

Input modelling for subchannel analysis of CANFLEX fuel bundle

The history of the technical, economic, and financial performances of these four countries' power companies over the past two decades is recounted, and then interpreted as the result of the existing organizational models. The changes that have occurred can be understood in long-term perspective by comparing the performance of these companies to the characteristics, rules, and objectives used to define the models, which also helps explain the history of performance indicator variations. Two models are defined: one for the physical plant and one for the management. These correspond to two successive phases in the organization and operation of the electrical sector. Rural electrification and regional interconnection will be important factors in any new model or models developed for the future, because the forms they take is ...

109

DNFB-DNS hapten-induced colitis in mice should not be considered a model of inflammatory bowel disease

This report describs the input modelling for subchannel analysis of CANFLEX fuel bundle using CASS(Candu thermalhydraulic Analysis by Subchannel approacheS) code which has been developed for subchannel analysis of CANDU fuel channel. CASS code can give the different calculation results according to users' input modelling. Hence, the objective of this report provide the background information of input modelling, the accuracy of input data and gives the confidence of calculation results. (author). 11 refs., 3 figs., 4 tabs.

1998-06-01

110

British Library Electronic Table of Contents (United Kingdom)

AbstractBackground: The dinitrofluorobenzene/dinitrosulfonic acid (DNFB/DNS) model was originally described as an experimental model of intestinal inflammation resembling human ulcerative colitis (UC). Due to the absence of acceptable UC experimental models for pharmacological preclinical assays, here we examine the immune response induced in this model. Methods: Balb/c mice were sensitized by skin application of DNFB on day 1, followed by an intrarectal challenge with DNS on day 5. We further expanded this model by administering a second DNS challenge on day 15. The features of colonic inflammation and immune response were evaluated. Results: The changes observed in colonic tissue corresponded, in comparison to the trinitrobenzene sulfonic acid (TNBS) colitis model, to a mild mucosal effe...

2011-01-01

111

Can Markov regime-switching models improve power-price forecasts? Evidence from German daily power prices

Can Markov regime-switching models improve power-price forecasts? Evidence from German daily power prices

Non-linear autoregressive Markov regime-switching models are intuitive. Time-series approaches for the modelling of electricity spot prices are frequently proposed. In this paper, such models are compared with an ordinary linear autoregressive model with regard to their forecast performances. The study is carried out using German daily spot-prices from the European Energy Exchange in Leipzig. Four non-linear models are used for the forecast study. The results of the study suggest that Markov regime-switching models provide better forecasts than linear models. (author)

2006-09-15

112

Reconnaissance radiological characterization for the White Point Nike Missile Site, San Pedro, California

Non-linear autoregressive Markov regime-switching models are intuitive. Time-series approaches for the modelling of electricity spot prices are frequently proposed. In this paper, such models are compared with an ordinary linear autoregressive model with regard to their forecast performances. The study is carried out using German daily spot-prices from the European Energy Exchange in Leipzig. Four non-linear models are used for the forecast study. The results of the study suggest that Markov regime-switching models provide better forecasts than linear models. (author)

2006-09-01

113

DOUBLE-SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

This report is the result of field work performed at the former White Point Nike Missile Site, San Pedro, California. The Hazardous Waste Remedial Actions Program tasked the Oak Ridge National Laboratory Pollutant Assessments Group in Grand Junction, Colo., with this project. The objective was to determine whether or not radioisotopes possibly associated with past Department of Defense (DOD) operations were present and within accepted background levels. The radiation survey was accomplished by performing three independent radiation surveys, both outdoors and indoors, and random soil sampling. Initially, the site was land surveyed to develop a grid block system. A background radiation investigation was performed out in the San Pedro area.

114

Performance optimization of the Packard 2000 CA/LL liquid scintillation counter for "1"4C dating

This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

2009-04-30

115

Prompt fission neutron energy spectra induced by fast neutrons

The ability of the Packard 2000 CA/LL liquid scintillation counter to reduce background count rates relies on pulse shape/duration analysis in which short duration organic scintillation events are discriminated from longer duration non-quenchable background events. A consequence of this is a loss in the counting efficiency. The results of this investigation indicate that much of the lost efficiency can be regained by sharpening the true #beta#"- pulse widths via the use of different scintillant combinations and by certain counter modifications. (author).

116

Beta and gamma decay heat measurements between 0.1s - 50,000s for neturon fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Progress report, June 1, 1992--December 31, 1994

Prompt fission neutron energy spectra for "2"3"5U and "2"3"9Pu have been measured for fission neutron energies greater than the energy of the incident neutrons inducing fission. The measurements were undertaken to investigate the shape dependence of the fission neutron spectra upon both the incident neutron energy and the mass of the nucleus undergoing fission. Measurements were made for both nuclides at incident neutron energies of 0.50, 1.50, 2.50 and 3.50 MeV. The data are presented either as relative yields or as ratios of measured spectra to that of "2"3"5U at 0.50 MeV. Incident neutrons were produced by the "7Li(p,n)"7Be reaction using a pulsed, bunched proton beam from the 5.5 MV Van de Graaff accelerator at the University of Massachusetts Lowell Radiation Laboratory. Fission neutrons were detected by a thin liquid scintillator with good time resolution capabilities. Neutron energies were determined by time-of-flight techniques with pulse-shape discrimination to reduce gamma-ray ...

117

A Fast Ionization Chamber for Fission Cross-Section Measurements at n(_)TOF

In the investigations reported here, a helium-jet/tape-transport system was used for the rapid transfer of fission products to a low-background environment where their aggregate beta and gamma-ray spectra were measured as a function of delay time after neutron induced fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Beta and gamma-ray energy distributions have been deduced for delay times as short as 0.2 s and extending out to 100,000s. Instrumentation development during the initial phase of the project included: (1) assembly and characterization of a NaI(Tl) spectrometer for determining aggregate gamma-ray energy distributions, (2) development and characterization of a beta spectrometer (having excellent gamma-ray rejection) for measuring aggregate beta-particle energy distributions, (3) assembly and characterization of a Compton-suppressed HPGe spectrometer for determining gamma-ray intensities of individual fission products to deduce fission-product yields. ...

1997-05-01

118

Modified-VSIMM algorithm with an application to the naval fire control technology

An ionization chamber with fast timing properties was built at CERN for measuring fission cross-sections of minor actinides at the n(_)TOF neutron beam. The design of this new chamber and of the front-end electronics was optimized to match the innovative features of the n(_)TOF facility, in particular the high instantaneous neutron flux and low background. For the most radioactive isotopes, a special version of the chamber, designed according to the ISO2919 standards, was built in order to comply with the radioprotection requirements at CERN. The detector and front-end electronics are here described, together with the simulated and measured response to fission fragments and #alpha#-particles. The performances of the chamber during the first measurement campaign at n(_)TOF are presented, focusing in particular on the fast time response, the good background rejection capability, low-background and high ...

2008-09-01

119

British Library Electronic Table of Contents (United Kingdom)

A modified variable structure interacting multiple model (M-VSIMM) estimator for complex hybrid maneuver target tracking is presented. The M-VSIMM could potentially be applied to fire control systems (FCS) used on warships. Target model groups were designed using 3D dimensional dynamic target models. Optimal model group selection logic was proposed, contrary to the activation and termination logic in the original VSIMM. The system will respond faster with optimal model group selection logic. After performing simulations, the tracking performances of the Kalman, ?-?(-?), VDIE, IMM and M-VSIMM filters were compared under various maneuvering conditions.

2011-01-01

120

Fluctuation properties of strength function phenomena: A model study

Developing a regulatory performance assessment approach for geological disposal of spent nuclear fuel

We study fluctuation properties of strength function phenomena by employing a quantum mechanical model where a single parent state couples with a large number of background states. The background system is devised in such a way that the classical dynamics of the system may show a regular, an irregular, or a chaotic character as a function of a single parameter. The coupling of the parent state to the background states produces a fragmentation of the parent state, giving rise to a strength function phenomenon. We study various measures of the strength function that characterize its bulk structure or fluctuation properties. They include energy moments, strength distribution, fractal dimensions of the strength function, and Fourier transform of the autocorrelation function. Some of these measures, such as strength distribution or Fourier transform of the autocorrelation function, reflect characteristic ...

1997-07-01

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121

Review of calculational models for the performance of CANDU-type nuclear fuel element and parametic study on the fuel performance

To be able to carry out review functions regulatory authorities must be able to make critical evaluations of proponent's safety cases. In Sweden the Swedish Radiation Safety Authority aims to have in place its own suite of performance assessment tools. This paper looks at the role and application of a regulator's models to important features of current modelling in a proponent's performance assessment. (authors)

122

An integrated approach to the modelling of hydrogen assisted failure in 316L steel

The LWR fuel performance analysis computer code, FRAPCON-1, are evaluated to investigate the performance of CANDU fuel elements loaded in Wolsung-1 reactor. The FRAPCON-1 models of neutron flux depression in fuel and of fuel-to-cladding heat transfer are modified, and the validity of fission gas release model for CANDU fuel is evaluated. And the heavy water properties are provided in calculating the heat transfer coefficient between cladding and coolant. By using the modified code, FRAPCON-1-CSK, the sensitivity studies are carried out for Wolsung-1 fuel element design parameters. The performance analysis is also performed for Wolsung-1 fuel elements. The calculated results are discussed in terms of LWR fuel design criteria because of unavailability of CANDU fuel design criteria. (Author).

1983-01-01

123

Evaluation of 1-site and 5-site models of methane on its adsorption on graphite and in graphitic slit pores.

An integrated approach to the modelling of hydrogen assisted failure in 316L steel is presented. The approach includes experimental, fractographic, numerical and theoretical analysis of the phenomenon. The physical adequacy of the mechanical models of hydrogen embrittlement (notch extension model and notch cracking model) is discussed by comparing the virtual damage depth (theoretical) predicted by the models with the embrittled zone (microphysical) measured in the fractographic analysis by scanning electron microscopy. In addition, a numerical modelling of hydrogen diffusion is performed, concluding that bulk diffusion is not important in hydrogen embrittlement of 316L steel, so that hydrogen transport accelerated by the microdamage itself should be taken into account. (orig.)

1998-09-01

124

The two-dimensional derivative-coupling model revisited

In this paper, we evaluate the performance of the 1- and 5-site models of methane on the description of adsorption on graphite surfaces and in graphitic slit pores. These models have been known to perform well in the description of the fluid-phase behavior and vapor-liquid equilibria. Their performance in adsorption is evaluated in this work for nonporous graphitized thermal carbon black, and simulation results are compared with the experimental data of Avgul and Kiselev (Chemistry and Physics of Carbon; Dekker: New York, 1970; Vol. 6, p 1). On this nonporous surface, it is found that these models perform as well on isotherms at various temperatures as they do on the experimental isosteric heat for adsorption on a graphite surface. They are then tested for their performance in predicting the adsorption isotherms in ...

2005-10-20

125

Program listing for heat-pump seasonal-performance model (SPM). [CNHSPM

Using the operator approach we reexamine the two-dimensional model describing a massive Fermi field interacting via derivative couplings with two massless Bose fields, one scalar and the other pseudoscalar. Performing a canonical transformation on the Bose field algebra, the Fermi field operator is written in terms of the Mandelstam soliton operator and the derivative-coupling (DC) model is mapped into the massive Thirring model with two vector-current-scalar-derivative interactions (Schroer-Thirring model). The DC model with massless fermions can be mapped into the massless Rothe-Stamatescu model with a Thirring interaction (massless Rothe-Stamatescu-Thirring model). Within the present approach the weak equivalence between the fermionic sector of the DC model and the massive Thirring ...

2007-05-11

126

Performance of a commercial heat pipe under operational conditions

The computer program CNHSPM is listed which predicts heat pump seasonal energy consumption (including defrost, cyclic degradation, and supplementary heat) using steady state rating point performance and binned weather data. (LEW)

1982-06-30

127

A new artificial bee swarm algorithm for optimization of proton exchange membrane fuel cell model parameters

The performance of a commercial heat pipe was investigated both experimentally and theoretically. The effect of the temperature difference, the surface area ratio, and the operational conditions on the performance were studied. The heat flow rate and the vapor temperature were estimated on a ready-made commercial heat pipe. Its performance varied considerably with operational conditions. Theoretical consideration of a mathematical model and several nomographs are also presented. This work is applicable to the design and use of heat pipes in the field.

1983-04-01

128

British Library Electronic Table of Contents (United Kingdom)

An appropriate mathematical model can help researchers to simulate, evaluate, and control a proton exchange membrane fuel cell (PEMFC) stack system. Because a PEMFC is a nonlinear and strongly coupled system, many assumptions and approximations are considered during modeling. Therefore, some differences are found between model results and the real performance of PEMFCs. To increase the precision of the models so that they can describe better the actual performance, optimization of PEMFC model parameters is essential. In this paper, an artificial bee swarm optimization algorithm, called ABSO, is proposed for optimizing the parameters of a steady-state PEMFC stack model suitable for electrical engineering applications. For studying the usefulness of the proposed algorithm, ABSO-based results...

2011-01-01

129

Properties of nuclear matter at small distances

Long-term storage of solar heat

Experimental data on high energy cumulative particle production are analyzed in the frame of flucton models. The performed analysis evidence for the flucton as a multiquark system with high baryon dnsity.

130

20 Watt-Hour Per Pound Regenerative Fuel Cell

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.

1981-06-01

131

Single charged top-pion production at next generation #gamma##gamma# colliders

... for evaluation of the electrochemiral performance of the materials and components used in EOS Rechargeable Fuel Cell Model RHO-24AH-Mod ...

1972-03-01

132

Underground Test Area Subproject Phase I Data Analysis Task. Volume VII - Tritium Transport Model Documentation Package

The future e"+e"- linear colliders can also operate in the e#gamma# or #gamma##gamma# modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process #gamma##gamma# #-># tb-bar#PI#_t"-. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode #PI#_t"- #-># bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in #gamma##gamma# mode at the TeV energy scale

2008-09-01

133

Underground Test Area Subproject Phase I Data Analysis Task. Volume VI - Groundwater Flow Model Documentation Package

Volume VII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the tritium transport model documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

1996-12-01

134

Robust distributed model predictive control: A review and recent developments

Volume VI of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the groundwater flow model data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

1996-11-01

135

British Library Electronic Table of Contents (United Kingdom)

Abstract This study presents a review of distributed model predictive control (DMPC) strategies followed by recent studies conducted by the authors on the robustness of these strategies to model errors and a summary of future challenges in this area. The review identifies three key challenges for the successful application of DMPC: (i) the selection of optimal control structure for DMPC; (ii) the choice of a suitable coordination strategy among the controllers; and (iii) the robustness of DMPC strategies to model errors. Then, the study summarises recent developments related to the robustness of unconstrained and constrained DMPC algorithms. For the unconstrained case, a methodology that is based on the calculation of a performance index is proposed to balance the trade-off between perform...

2011-01-01

136

Model tests on a semi-axial pump turbine

Assessing predictive skill of models to optimise crop management and design

Due to their good hydraulic characteristic semi-axial pump turbines are used in the medium head range of pumped storage plants. This paper describes model tests performed on a semiaxial pump turbine model and shows the results of these tests. The aim of the model tests was the optimization of the hydraulic water passage, the measurement of the hydraulic characteristics over the whole operating range, the investigation of the cavitation behaviour, the investigation of the hydraulic forces and torques as well as the proof of the values guaranteed to the customer.

1984-03-01

137

Environmental Research Database

DescriptionAn ability to foresee impacts on output is invaluable to any industry; good prediction is the basis of good management. Many research models can predict crop performance, but the skill (used here to include accuracy, precision, facility and credibility) of these predictions is rarely assessed, so is not well known. The only research model successfully adopted for practical purposes in the UK is the Broom's Barn Beet Model. Thus we propose here, research to assess and publish the skill of the [continued...

2004-01-30

138

Analysis of myocardial time-activity curves of /sup 123/I-heptadecanoic acid. Pt. 1. Curve fitting

Generalizing Boolean Satisfiability I: Background and Survey of Existing Work

Myocardial time-activity curves can be described by two or more parameters. To establish the optimal curve fitting method 33 myocardial time-activity curves were analyzed with different curve fitting methods: monoexponential, biexponential and monoexponential plus constant. A background correction was not applied. Biexponential curve fitting resulted in redundancy of parameters. Optimal curve fitting was obtained with monoexponential plus constant. The constant represents the background activity together with the stores radiolabelled lipids and the half-time value represents the wash-out of radioiodide from the myocardium. A strong relation was found between the constant and the half-time value: small errors in the determination of the constant (background activity) resulted in considerable errors of the half-time value. It is concluded that optimal analysis of a myocardial time-activity curve can be ...

1987-12-01

139

Thulium-doped vanadate crystals: Growth, spectroscopy and laser performance

This is the first of three planned papers describing ZAP, a satisfiability engine that substantially generalizes existing tools while retaining the performance characteristics of modern high-performance solvers. The fundamental idea underlying ZAP is that many problems passed to such engines contain rich internal structure that is obscured by the Boolean representation used; our goal is to define a representation in which this structure is apparent and can easily be exploited to improve computational performance. This paper is a survey of the work underlying ZAP, and discusses previous attempts to improve the performance of the Davis-Putnam-Logemann-Loveland algorithm by exploiting the structure of the problem being solved. We examine existing ideas including extensions of the Boolean language to allow cardinality constraints, pseudo-Boolean representations, symmetry, and a limited form of ...

2011-01-01

140

British Library Electronic Table of Contents (United Kingdom)

This work is concentrated on growth, spectroscopy and laser performance of thulium-doped vanadate crystals. At the beginning the growth techniques are analyzed and then the matrix of vanadates crystal, its structure and physicochemical properties are explained together with the rare earth activators influence. Detailed spectroscopy of the thulium-doped vanadate crystals then follows. On the background of this theoretical analysis and state of the art of the subject the description of thulium vanadate lasers (especially Tm:YVO"4, Tm:GdVO"4, and Tm:LuVO"4) together with their generated output radiation characteristics are presented.

2011-01-01

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141

Performance of the transition radiation detector flown on the NMSU/WIZARD TS93 balloon-borne instrument

Improved SSAMS performance

It is built and tested a transition radiation detector (TRD) to discriminate positrons from protons in the balloon flight TS 93 experiment. It is presented the TRD performance using flight data obtaining a proton-positron rejection factor of the order of 10{sup -3}. During the 24 hour flight, the data in the momentum range 4-50 GeV/c are collected. Using the TRD together with the Silicon calorimeter, it is achieved an overall rejection factor of about 10{sup -5} of positron against the proton background over the entire momentum range.

1995-09-01

142

British Library Electronic Table of Contents (United Kingdom)

We operate a new NEC 250kV single-stage accelerator mass spectrometer (SSAMS) next to our established 5MV tandem. This permits good comparison of 14C-AMS and challenges SSAMS performance. Initial SSAMS ion-optical deficiencies have been addressed by shimming the injection magnet and 3permil 14C/13C measurement with background limited by sample chemistry is routine. Higher-precision analysis is also achievable. A problematic measurement interference remains, however. The small spectrometer was procured to add measurement capacity, and for experiments with positive ions, but is now the preferred instrument for both convenience and measurement quality.

2010-01-01

143

Heavy flavor production at the Tevatron

Evaluation of Aution Max AX-4030 and 9UB Uriflet, 10PA Aution Sticks urine dipsticks in the automated urine test strip analysis.

The authors discuss some of the results on the measurements of heavy flavor production at the Tevatron. Heavy flavor production can be used to test QCD over a wide range of quark masses (m{sub b} {approx} 4.5 GeV/c{sup 2} to m{sub t} = 174.3 {+-} 5.1 GeV/c{sup 2}). In addition, it is a background that has to be understood to perform physics measurements in the top sector and Higgs searches. The results reported here are performed using the Run1 data collected at Tevatron ({approx} 100 pb{sup -1}).

2002-10-16

144

Analysis of thermal comfort and indoor air quality in a mechanically ventilated theatre

Abstract Background: Aution Max AX-4030, a test strip analyzer recently introduced to the market, represents an upgrade of the Aution Max AX-4280 widely employed for urinalysis. This new instrument model can allocate two different test strips at the same time. In the present study the two instruments have been compared together with the usage of Uriflet 9UB and the recently produced Aution Sticks 10PA urine strips, the latter presenting an additional test area for the measurement of urinary creatinine. Methods: Imprecision and correlation between instruments and strips have been evaluated for chemical-physical parameters. Accuracy was evaluated for protein, glucose and creatinine by comparing the semi-quantitative results to those obtained by quantitative methods. The well-known interference effect of high ascorbic acid levels on urine glucose test strip determination was evaluated, ascorbic acid influence was also evaluated on protein and ...

2011-09-26

145

The ANL electrochemical program for DOE on electric vehicle R&D. Quarterly progress report, January--March 1991

Theatres are the most complex of all auditorium structures environmentally. They usually have high heat loads, which are of a transient nature as audiences come and go, and from lighting which changes from scene to scene, and they generally have full or nearly full occupancy. Theatres also need to perform well acoustically, both for the spoken word and for music, and as sound amplification is less used than in other auditoria, background noise control is critically important. All these factors place constraints on the ventilation design, and if this is poor, it can lead to the deterioration of indoor air quality and thermal comfort. To analyse the level of indoor air quality and thermal comfort in a typical medium-sized mechanically ventilated theatre, and to identify where improvements could typically be made, a comprehensive post-occupancy evaluation study was carried out on a theatre in Belgrade. The evaluation, based on the results of ...

2008-07-01

146

The ANL electrochemical program for DOE on electric vehicle R D

This report summarizes the objectives, background, technical progress, and status of ANL electric vehicle battery R&D tasks for DOE-EHP during the period of January 1 through March 31, 1991. The work is organized into the following six task areas: Project management; battery systems technology; lithium/sulfide batteries; advanced sodium/metal chloride battery; aqueous batteries; and EV Battery performance/life evaluation.

1991-12-31

147

Performance of the transition radiation detector in D{Phi}

This report summarizes the objectives, background, technical progress, and status of ANL electric vehicle battery R D tasks for DOE-EHP during the period of January 1 through March 31, 1991. The work is organized into the following six task areas: Project management; battery systems technology; lithium/sulfide batteries; advanced sodium/metal chloride battery; aqueous batteries; and EV Battery performance/life evaluation.

1991-01-01

148

Identification of Dimethyldioctadecylammonium Ion (m/z 550.6) and Related Species (m/z 522.6, 494.6) as a Source of Contamination in Mass Spectrometry

The transition radiation detector (TRD) for the D{Phi} experiment is currently in operation at Fermilab. Transition radiation production, which has been clearly observed in the collider data, makes the TRD a valuable tool to discriminate electrons and hadrons. We describe an algorithm based on the truncated energy, and illustrate its use for top signal and background. (authors). 7 refs., 6 figs., 2 tabs.

1994-12-31

149

NATGAS. A Model of the European Natural Gas Market

Chemical contamination can be one of the more common problems encountered when performing trace-level analysis regardless of the analytical technique. Minimizing or eliminating background interferences...Full Text Available

2008-05-01

150

Numerical solutions of high-frequency perturbations in Bianchi type IX models

The NATural GAS model is an integrated model of the European wholesale gas market providing long-run projections of supply, transport, storage and consumption patterns in the model region, aggregated in 5-year periods, distinguishing two seasons (winter and summer). Model results include levels of investment in the various branches, output and consumption, depletion of reserves and price levels. The NATGAS model computes long-term effects of policy measures on future gas production and gas prices in Europe. NATGAS is an equilibrium model describing behaviour of gas producers, investors in infrastructure (pipeline, LNG capacity, as well as storage), traders and consumers. NATGAS covers the main European demand regions, including the United Kingdom, Germany, the Netherlands and Italy. Moreover, it covers the main origins of supply on the European market, such as ...

2006-01-01

151

Indirect Dark Matter Signals from EGRET and PAMELA compared

The problem in perturbation theory in general relativity is finding a natural gauge which simplifies the equations considerably. We solved the first and second order perturbation equations in the ''Lorentz gauge'' using the two-timing method. The equations were deduced from the equations of Einstein in the presence of a matter energy-momentum tensor of a perfect fluid with equation of state p = (#gamma#-1) rho. It is found that the 0--0 component of the first order equations together with the gauge conditions are consistent with the Bianchi type V model, without axial symmetry. It represents a ''ground state'' situation of the Bianchi type IX model (Mixmaster model.) The second order equations, describing the reaction back of the gravitational waves on the slowly varying background, give rise to rotation and will disturb the isotropization mechanism. The numerical solutions show all the features which ...

152

Dietary plant materials reduce acrylamide formation in cookie and starch-based model systems

Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET shows all the features expected from DMA. The new precise measurements of the antiproton and positron fractions from PAMELA are compared with the EGRET excess. It is shown that the charged particles are strongly dependent on the propagation model used. The usual propagation models with isotropic propagation models are incompatible with the recently observed convection in our Galaxy. Convection leads to an order of magnitude uncertainty in the yield of charged particles from DMA, since even a rather small convection will let drift the charged particles in the halo to outer space. It is shown that such anisotropic propagation models including convection prefer a ...

2009-01-01

153

British Library Electronic Table of Contents (United Kingdom)

Abstract BACKGROUND: Dietary plant materials have attracted much attention because of their health benefits to humans. Acrylamide is found in various heated carbohydrate-rich foods. Our previous results showed that crude aqueous extracts from diverse dietary plants and some phenolic compounds could mitigate acrylamide formation in an asparagine-glucose model system. Based on our previous study, several plant materials were selected to further investigate their inhibitory effects on acrylamide formation in cookies and starch-based model systems. RESULTS: Addition of raw powders from selected dietary plants and their crude aqueous extracts could considerably reduce acrylamide formation in both cookie and potato starch-based models. Aqueous extracts of clove at 4% caused the largest reduction...

2011-01-01

154

Atmospheric Gravity Perturbations Measured by Ground-Based Interferometer with Suspended Mirrors

Modeling of batteries and fuel cells; Proceedings of the Symposium, Phoenix, AZ, Oct. 13-19, 1991

A possibility of geophysical measurements using the large scale laser interferometrical gravitational wave antenna is discussed. An interferometer with suspended mirrors can be used as a gradiometer measuring variations of an angle between gravity force vectors acting on the spatially separated suspensions. We analyze restrictions imposed by the atmospheric noises on feasibility of such measurements. Two models of the atmosphere are invoked: a quiet atmosphere with a hydrostatic coupling of pressure and density and a dynamic model of moving region of the density anomaly (cyclone). Both models lead to similar conclusions up to numerical factors. Besides the hydrostatic approximation, we use a model of turbulent atmosphere with the pressure fluctuation spectrum f^{-7/3} to explore the Newtonian noise in a higher frequency domain (up to 10 Hz) predicting the gravitational noise ...

2003-01-01

155

Core Heat Transfer Model Validation of the TASS/SMR-S Code using the Bennett's Test

The present volume on modeling of batteries and fuel cells discusses the significance of the effectiveness factor for flooded porous electrodes, active pore distribution spectroscopy for characterizing porous battery electrodes, the agglomerate model for porous electrodes, and dynamic-performance measurements of battery cells for electric vehicles and other applications. Attention is given to mathematical modeling of a primary zinc/air battery, mathematical modeling of Grace Li-TiS2 cells, modeling of electrocrystallization processes in battery systems, and rotating disk electrode studies in molten Li/K carbonate eutectic. Topics addressed include the variability of nickel oxide cathode dissolution in molten carbonate fuel cells, water transport properties of fuel cell ionomers, modeling water content effects in polymer electrolyte fuel ...

1991-01-01

156

Performance estimates for attached-sunspace passive solar heated buildings

The SMART (System-integrated Modular Advanced ReacTor) which is a 330 MWt advanced integral PWR was developed by the KAERI (Korea Atomic Energy Institute) for electricity generation and seawater desalination. A thermal hydraulic evaluation and analysis of the SMART is performed by the TASS /SMR-S (Transient And Setpoint Simulation/System integrated Modular Reactor-Safety). The TASS/SMR-S code has various models reflecting the design features of the SMART such as the drift flux model, the core models (core power and core heat transfer model), the component models, and the specific models. One of the core models is the core heat transfer model. The role of this model is to calculate the heat flux and radial temperature profiles at a fuel rod surface using the relevant heat transfer ...

2010-10-01

157

High Performance Electrical Modeling and Simulation Verification Test Suite - Tier I; TOPICAL

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.

1980-01-01

158

High Performance Electrical Modeling and Simulation Verification Test Suite - Tier I

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.

2001-12-01

159

The Risk of Paradoxical Embolism (RoPE) Study: Developing risk models for application to ongoing randomized trials of percutaneous patent foramen ovale closure for cryptogenic stroke

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.

2001-12-01

160

Spatial dependency of V. cholera prevalence on open space refuse dumps in Kumasi, Ghana: a spatial statistical modelling

BackgroundDespite the diffusion into practice of percutaneous closure of a patent foramen ovale (PFO) in patients with cryptogenic stroke (CS), the benefits have not been demonstrated,...Full Text Available

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161

Rotation in string cosmology

BackgroundCholera has persisted in Ghana since its introduction in the early 70's. From 1999 to 2005, the Ghana Ministry of Health officially reported a total of 26,924 cases and...Full Text Available

162

Rotation in string cosmology

We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant)

2003-03-21

163

Measurements of radioactivity in Jamaican building materials and gamma dose equivalents in a prototype red mud house

We describe exact cosmological solutions with rotation and expansion in the low-energy effective string theory. These models are spatially homogeneous (closed Bianchi type IX) and they belong to the family of shear-free metrics which are causal (no closed timelike curves are allowed), admit no parallax effects and do not disturb the isotropy of the background radiation. The dilaton and the axion fields are nontrivial, in general, and we consider both cases with and without the central charge (effective cosmological constant).

2003-03-21

164

How do patient characteristics influence informal payments for inpatient and outpatient health care in Albania: Results of logit and OLS models using Albanian LSMS 2005

Concentrations of 226Ra, 232Th, and 40K measured in bauxite waste, local building materials, and soils are presented and used in model equations to estimate the effective gamma dose-equivalent increments over background in the center of a standard-sized room in a prototype house. Calculated and measured values compare reasonably well.

165

Closed-string tachyon condensation and loop corrected on-shell effective action of open-string tachyons

BackgroundInformal payments for health care are common in most former communist countries. This paper explores the demand side of these payments in Albania. By using data from the...Full Text Available

166

A modeling study by response surface methodology and artificial neural network on culture parameters optimization for thermostable lipase production from a newly isolated thermophilic Geobacillus sp. strain ARM

We propose a basic strategy to obtain a consistent on-shell effective action of open-string tachyons, on the background where closed-string tachyons are already condensed. We use sigma-model approach, basically. We regard D-instanton-like objects with appropriate weight as closed-string tachyon tadpoles, and we insert them into worldsheets to analyze the effect of closed-string tachyons.

2002-01-23

167

A Search for electron neutrino appearance at the Delta m**2 ~ 1- eV**2 scale

BackgroundThermostable bacterial lipases occupy a place of prominence among biocatalysts owing to their novel, multifold applications and resistance to high temperature and other...Full Text Available

168

Markov random fields simulation: an introduction to the stochastic modelling of petroleum reservoirs; Simulacao de campos aleatorios markovianos: uma introducao voltada a modelagem estocastica de reservatorios de petroleo

The MiniBooNE Collaboration reports first results of a search for {upsilon}{sub e} appearance in a {upsilon}{sub {mu}} beam. With two largely independent analyses, we observe no significant excess of events above background for reconstructed neutrino energies above 475 MeV. The data are consistent with no oscillations within a two neutrino appearance-only oscillation model.

2007-04-01

169

AFS Cupola Model Verification--Initial Investigations

Stochastic simulation has been employed in petroleum reservoir characterization as a modeling tool able to reconcile information from several different sources. It has the ability to preserve the variability of the modeled phenomena and permits transference of geological knowledge to numerical models of flux, whose predictions on reservoir constitute the main basis for reservoir management decisions. Several stochastic models have been used and/or suggested, depending on the nature of the phenomena to be described. Markov Random Fields (MRFs) appear as an alternative for the modeling of discrete variables, mainly reservoirs with mosaic architecture of facies. In this dissertation, the reader is introduced to the stochastic modeling by MRFs in a generic sense. The main aspects of the technique are reviewed. MRF Conceptual Background is ...

1998-02-01

170

Use of single-well simulators and economic performance criteria to optimize fracturing treatment design

The cupola furnace is used to melt scrap steel, pig iron, foundry returns, and alloying additives to a prescribed tapping chemistry and temperature for iron casting applications. The melting process within the cupola is highly complex and not well quantified. The American Foundrymen's Society is developing a mathematical model to aid in the understanding of these processes. This model is reaching maturity, and has been successful in estimating a number of melting parameters. This paper details the results of efforts to verify the model in a controlled system, equipped wit the appropriate sensors, for model verification. The work was performed on a research-scale cupola furnace located at the Department of Energy's Albany Research Center.

1998-01-01

171

Modeling pitting corrosion damage of high-level radioactive-waste containers, with emphasis on the stochastic approach

Low-permeability reservoirs are currently being propped with sand, resin-coated sand, intermediate-density proppants, and bauxite. This wide range of proppant cost and performance has resulted in the proliferation of proppant selection models. Initially, a rather vague relationship between well depth and proppant strength dictated the choice of proppant. More recently, computerized models of varying complexity that use net-present-value (NPV) calculations have become available. The input is based on the operator's performance goals for each well and specific reservoir properties. Simpler, noncomputerized approaches include cost/performance comparisons and nomographs. Each type of model, including several of the computerized models, is examined here. By use of these models and NPV calculations, optimum fracturing ...

1990-02-01

172

Computer modeling of electrical performance of detonators

Recent efforts to identify methods of modeling pitting corrosion damage of high-level radioactive-waste containers are described. The need to develop models that can provide information useful to higher level system performance assessment models is emphasized, and examples of how this could be accomplished are described. Work to date has focused upon physically-based phenomenological stochastic models of pit initiation and growth. These models may provide a way to distill information from mechanistic theories in a way that provides the necessary information to the less detailed performance assessment models. Monte Carlo implementations of the stochastic theory have resulted in simulations that are, at least qualitatively, consistent with a wide variety of experimental data. The effects of environment on pitting corrosion ...

1993-01-01

173

A parametric analysis of decay ratio calculations in a boiling water reactor model

An empirical model of detonator electrical performance which describes the resistance of the exploding bridgewire (EBW) or exploding foil initiator (EFI or slapper) as a function of energy, deposition will be described. This model features many parameters that can be adjusted to obtain a close fit to experimental data. This has been demonstrated using recent experimental data taken with the cable discharge system located at Sandia National Laboratories. This paper will be a continuation of the paper entitled ``Cable Discharge System for Fundamental Detonator Studies`` presented at the 2nd NASA/DOD/DOE Pyrotechnic Workshop.

1995-05-01

174

Somatic effects in nuclear medicine and radiology

The results of an investigation of the effects of several parameters on the reactivity instability of a Boiling Water Reactor (BWR) calculational model are summarized. Calculations were performed for a typical BWR operated at low flow conditions, where reactivity instabilities are more likely to occur. The parameters investigated include the axial power shape (characterized by two separate parameters), the core pressure, and operating flow. All calculations were performed using the LAPUR code which was developed at the Oak Ridge National Laboratory for the dynamic modeling of large BWR's. 4 refs., 8 figs.

1989-01-01

175

A unified analysis of the reactor neutrino program towards the measurement of the theta_13 mixing angle

Probable risks for the occurrence of somatic effects due to diagnostic radiology and nuclear medicine are summarised. The biological background of radiation carcinogenesis and epidemiological results are discussed. At the Leiden University Medical Centre the average effective dose per examination due to diagnostic radiology and nuclear medicine amount to 0.95 and 4.4 mSv, respectively. These values correspond well with the average values of 0.82 and 3.0 mSv reported for The Netherlands as a whole. Since radiological examinations are performed at a much larger frequency than nuclear medicine the relative collective dose for the first type of examinations is higher than the latter. Risk for occurency of malignancies are at least one order of magnitude lower than the hypothetical risk due to the background radiation typical of The Netherlands.

1999-01-01

176

Computation of a turbulent natural convection in a rectangular cavity with the low-Reynolds-number differential stress and flux model

We present in this article a detailed quantitative discussion of the measurement of the leptonic mixing angle theta_13 through currently scheduled reactor neutrino oscillation experiments. We thus focus on Double Chooz (Phase I & II), Daya Bay (Phase I & II) and RENO experiments. We perform a unified analysis, including systematics, backgrounds and accurate experimental setup in each case. Each identified systematic error and background impact has been assessed on experimental setups following published data when available and extrapolating from Double Chooz acquired knowledge otherwise. After reviewing the experiments, we present a new analysis of their sensitivities to sin^2(2 theta_13) and study the impact of the different systematics based on the pulls approach. Through this generic statistical analysis we discuss the advantages and drawbacks of each experimental setup.

2007-01-01

177

Effects of livestock wastewater variety and disinfectants on the performance of constructed wetlands in organic matters and nitrogen removal

A numerical study of a natural convection in a rectangular cavity with the low-Reynolds-number differential stress and flux model is presented. The primary emphasis of the study is placed on the investigation of the accuracy and numerical stability of the low-Reynolds-number differential stress and flux model for a natural convection problem. The turbulence model considered in the study is that developed by Peeters and Henkes (1992) and further refined by Dol and Hanjalic (2001), and this model is applied to the prediction of a natural convection in a rectangular cavity together with the two-layer model, the shear stress transport model and the time-scale bound #upsilon#"2-f model, all with an algebraic heat flux model. The computed results are compared with the experimental data commonly used for the validation of the ...

2004-10-01

178

British Library Electronic Table of Contents (United Kingdom)

Background, aim and scope Treatment performance of constructed wetlands (CWs) is largely dependent on the characteristics of the wastewater. Although livestock wastewater is readily biodegradable in general, its variety in biodegradability can still be significant in practice. In addition, it is a common practice to periodically use disinfectants in livestock activities for health concerns. Obviously, the residual of the disinfectants in livestock wastewater may have serious inhibitory effect on the microbial activities during wastewater treatment. Thus, the main objective of this study was to examine the variety of livestock wastewater in biodegradability and its effect on the performance of a pilot scale tidal flow CWs (TFCWs) in organic matter and nitrogen removal. Furthermore, investig...

2011-01-01

179

Probabilistic approach for model and data uncertainties and its experimental identification in structural dynamics: Case of composite sandwich panels

Performance improvement of quantum dot infrared photodetectors through modeling

This paper deals with the experimental identification and the validation of a non-parametric probabilistic approach allowing model uncertainties and data uncertainties to be taken into account in the numerical model developed to predict low- and medium-frequency dynamics of structures. The analysis is performed for a composite sandwich panel representing a complex dynamical system which is sufficiently simple to be completely described and which exhibits, not only data uncertainties, but above all model uncertainties. The dynamical identification is experimentally performed for eight panels. The experimental frequency response functions are used to identify the non-parametric probabilistic approach of model uncertainties. The prediction of the low- and medium-frequency dynamical responses obtained with the stochastic system is compared with the experimental ...

2006-06-01

180

British Library Electronic Table of Contents (United Kingdom)

This paper presents a method to evaluate and improve the performance of quantum dot infrared photodetectors (QDIPs). We proposed a device model for QDIPs. The developed model accounts for the self-consistent potential distribution, features of the electron capture and transport in realistic QDIPs in dark and illumination conditions. This model taking the effect of donor charges on the spatial distribution of the electric potential in the QDIP active region. The model is used for the calculation of the dark current, photocurrent and detectivity as a function of the structural parameters such as applied voltage, doping QD density, QD layers, and temperature. It explains strong sensitivity of dark current to the density of QDs and the doping level of the active region. In order to confirm our...

2010-01-01

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181

Numerical investigation of the impact of gas and cooling flow configurations on current and water distributions in a polymer membrane fuel cell through a pseudo-two-dimensional diphasic model

British Library Electronic Table of Contents (United Kingdom)

For optimal performances, proton exchange membrane fuel cells require fine water and thermal management. Accurate modelling of the physical phenomena occurring in the fuel cell is a key issue to improve fuel cell technology. Here, an analytic steady state diphasic 2D model of heat and mass transfer is presented. Through this model, the aim of this work is to study the influence of local events on the global performances of a fuel cell. A part of the complete model is a microscopic representation of the coupling between water transport and charge transfers in the electrodes. The thickness of the liquid layer around the reactive agglomerates is deduced from the saturation. The evolution of the quantity of water within the catalyst layer is monitored and its influence on the global performanc...

2010-01-01

182

Development of Seismic Analysis Model and Time History Analysis for KALIMER-600

Mercury modeling for PWSCC length sizing. [Primary water stress corrosion cracking

This report describes a simple seismic analysis model of the KALIMER-600 sodium cooled fast reactor and its application to the seismic time history analysis. To develop the simple seismic analysis model, the detailed 3-D finite element analyses for main components, IHTS piping system, and reactor building were carried out to verify the dynamic characteristics of each part of simple seismic analysis models. By using the developed simple model, the seismic time history analyses for both cases of a seismic isolation and non-isolation design of KALIMER-600 were performed. From the comparison of the calculated floor response spectrum, it is verified that the seismically isolated KALIMER-600 reactor building shows a great performance of a seismic isolation and assures a seismic integrity.

2007-02-15

183

Mercury modeling for PWSCC length sizing. [Primary water stress corrosion cracking

This report describes the results of EPRI Program S404-28, titled Experimental Modeling of Eddy Current Response'', conducted by the Westinghouse Science and Technology Center (STC). The Westinghouse STC demonstrates that its mercury modeling technique provides an unique bridge between steam generator eddy current field inspection conditions and predictions obtained using recently developed analytical models. The mercury modeling technique was used systematically to explore factors which contribute to primary water stress corrosion cracking (PWSCC) sizing inaccuracy, including probe design, coil excitation frequency, crack length, and crack morphology. Two new proposed techniques for inverting crack lengths from eddy current data are compared with the technique commonly used in field data analysis for PWSCC. The performance of uniform field eddy current probes is ...

1992-08-01

184

Topological modeling of the reactive capacity and biological activity of some amino-polysaccharides

This report describes the results of EPRI Program S404-28, titled Experimental Modeling of Eddy Current Response'', conducted by the Westinghouse Science and Technology Center (STC). The Westinghouse STC demonstrates that its mercury modeling technique provides an unique bridge between steam generator eddy current field inspection conditions and predictions obtained using recently developed analytical models. The mercury modeling technique was used systematically to explore factors which contribute to primary water stress corrosion cracking (PWSCC) sizing inaccuracy, including probe design, coil excitation frequency, crack length, and crack morphology. Two new proposed techniques for inverting crack lengths from eddy current data are compared with the technique commonly used in field data analysis for PWSCC. The performance of uniform field eddy current probes is ...

1992-08-01

185

British Library Electronic Table of Contents (United Kingdom)

The work is devoted to a microscopic analysis of the reactive capacity of chitin. An algorithm for modeling the deacetylation reaction in a monomeric unit of chitin is described. The reaction coordinate and the potential energy surface topography are determined taking into account the electron-vibrational interaction and low-symmetry perturbations within Jahn-Teller theory. Based on this algorithm, the topological modeling of the deacetylation process is performed for the first time and a mechanism of the biological activity of chitosan is proposed.

2011-01-01

186

Study of flows in a cyclone chamber

British Library Electronic Table of Contents (United Kingdom)

Parameters of the vortex air flow in an isothermal model of the cyclone chamber are studied. The effect of the air velocity in nozzles on the values and character of the distribution of pressure and tangential and longitudinal velocities of air in the chamber is determined. Numerical modeling of the flow is performed, and it is shown that numerical calculation by the k-w turbulence model is in agreement with experimental data.

2011-01-01

187

Studies of neural networks for engine control: application to the electromechanical valves engine; Etudes des reseaux de neurones pour le controle moteur: application a soupapes electromecaniques

Magnetic flocculation and filtration

This paper deals with the control of an electromechanical valves engine. The control uses neural networks in order to build a non-linear model of engine filing which depends on the driven inlets. The aim is to build this real-time model and to integrate this model to a control system which performs an iterative inversion. (J.S.)

1997-12-31

188

Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

1996-10-01

189

QTL mapping in outbred half-sib families using Bayesian model selection.

This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB ...

2005-12-15

190

Oil Spill Simulation and Validation in the Arabian (Persian) Gulf with Special Reference to the UAE Coast

In this article, we propose a model selection method, the Bayesian composite model space approach, to map quantitative trait loci (QTL) in a half-sib population for continuous and binary traits. In our method, the identity-by-descent-based variance component model is used. To demonstrate the performance of this model, the method was applied to map QTL underlying production traits on BTA6 in a Chinese half-sib dairy cattle population. A total of four QTLs were detected, whereas only one QTL was identified using the traditional least square (LS) method. We also conducted two simulation experiments to validate the efficiency of our method. The results suggest that the proposed method based on a multiple-QTL model is efficient in mapping multiple QTL for an outbred half-sib population and is more powerful than the LS method based on a single-QTL ...

2011-04-13

191

British Library Electronic Table of Contents (United Kingdom)

The use of numerical modeling in oil spill incidents is a well established technique that has proven to provide cost-effective and reasonable estimates of oil surface drift. Good predictability of such models depends highly on the quality of the input data of the incident and on the model calibration effort. This paper presents the results of simulating oil spillage trajectory in the Arabian (Persian) Gulf. The study employed a 3-D rectilinear hydrodynamic model combined with oil spill model. Typical representative environmental conditions of the Arabian Gulf were first setup into a hydrodynamic circulation model using data from various sources. The performance of the hydrodynamic model was then tested against measurements of tidal fluctuation and sea currents at selected locations. The sp...

2007-01-01

192

Assessment of periodic sub-diurnal Earth rotation variations at tidal frequencies through transformation of VLBI normal equation systems

British Library Electronic Table of Contents (United Kingdom)

We present an empirical model for periodic variations of diurnal and sub-diurnal Earth rotation parameters (ERPs) that was derived based on the transformation of normal equation (NEQ) systems of Very Long Baseline Interferometry (VLBI) observing sessions. NEQ systems that contain highly resolved polar motion and UT1-TAI with a temporal resolution of 15?min were generated and then transformed to the coefficients of the tidal ERP model to be solved for. To investigate the quality of this model, comparisons with empirical models from the Global Positioning System (GPS), another VLBI model and the model adopted by the conventions of the International Earth Rotation and Reference Systems Service (IERS) were performed. The absolute coefficients of these models agree almost completely within 7.5?...

2011-01-01

193

A patient specific electro-mechanical model of the heart

British Library Electronic Table of Contents (United Kingdom)

This paper presents a patient specific deformable heart model that involves the known electrical and mechanical properties of the cardiac cells and tissue. The whole heart model comprises ten Tusscher's ventricular and Nygren's atrial cell models, the anatomical and electrophysiological model descriptions of the atria (introduced by Harrild et al.) and ventricle (given by Winslow et al.), and the mechanical model of the periodical cardiac contraction and resting phenomena proposed by Moireau et al. During the propagation of the depolarization wave, the kinetic, compositional and rotational anisotropy is handled by the tissue, organ and torso model. The applied patient specific parameters were determined by an evolutionary computation method. An intensive parameter reduction was performed u...

2011-01-01

194

New neutron capture and total cross section measurements on {sup 88}Sr and their impact on s-process nucleosynthesis

Mode shape and natural frequency identification for seismic analysis from background vibration

The authors have made new and improved measurements of the neutron capture and total cross sections of {sup 88}Sr at the Oak Ridge Electron Linear Accelerator (ORELA). Improvements over previous measurements include a wider incident neutron energy range, the use of metallic rather than carbonate samples, better background subtraction, reduced sensitivity to sample-dependent backgrounds, and better pulse-height weighting functions. Because of its small cross section, the {sup 88}Sr(n,{gamma}) reaction is an important bottleneck during the s-process nucleosynthesis. Hence, an accurate determination of this rate is needed to better constrain the neutron exposure in s-process models and to more fully exploit the recently discovered isotopic anomalies in certain meteorites. They describe the experimental procedures, compare the results to previous data, and discuss their astrophysical impact.

1998-11-01

195

Mitochondrial DNA background modulates the assembly kinetics of OXPHOS complexes in a cellular model of mitochondrial disease

Background vibration in a CANDU plant can be used to determine the dynamic characteristics of major items of equipment, such as calandria, the fuelling machines and the primary heat transport pumps. These dynamic characteristics can then be used to verify the seismic response of the equipment which, at present, is based on theoretical models only. The feasibility and basic theory of this new approach (which uses accelerations measured at several points on a structure and does not require knowledge of the source of excitation) was established in Phase I of the study. This report is based on Phase II in which the methods of analysis developed in Phase I were improved and verified experimentally. A Fast Fourier Transform (FFT) algorithm was incorporated and an interactive curve fitting technique was developed to obtain the dynamic characteristics in the form of natural frequencies, mode shapes and damping ratios. The method is now available for ...

1984-02-06

196

British Library Electronic Table of Contents (United Kingdom)

Lebers hereditary optic neuropathy (LHON), the most frequent mitochondrial disorder, is mostly due to three mitochondrial DNA (mtDNA) mutations in respiratory chain complex I subunit genes: 3460/ND1, 11778/ND4 and 14484/ND6. Despite considerable clinical evidences, a genetic modifying role of the mtDNA haplogroup background in the clinical expression of LHON remains experimentally unproven. We investigated the effect of mtDNA haplogroups on the assembly of oxidative phosphorylation (OXPHOS) complexes in transmitochondrial hybrids (cybrids) harboring the three common LHON mutations. The steady-state levels of respiratory chain complexes appeared normal in mutant cybrids. However, an accumulation of low molecular weight subcomplexes suggested a complex I assembly/stability defect, which was ...

2008-01-01

197

Discriminating between a Stochastic Gravitational Wave Background and Instrument Noise

Positrons and antiprotons from inert doublet model dark matter

The detection of a stochastic background of gravitational waves could significantly impact our understanding of the physical processes that shaped the early Universe. The challenge lies in separating the cosmological signal from other stochastic processes such as instrument noise and astrophysical foregrounds. One approach is to build two or more detectors and cross correlate their output, thereby enhancing the common gravitational wave signal relative to the uncorrelated instrument noise. When only one detector is available, as will likely be the case with the Laser Interferometer Space Antenna (LISA), alternative analysis techniques must be developed. Here we show that models of the noise and signal transfer functions can be used to tease apart the gravitational and instrument noise contributions. We discuss the role of gravitational wave insensitive "null channels" formed from particular combinations of the time delay interferometry, and ...

2010-01-01

198

An alternative explanation of the COBE data

We investigate the signatures of antimatter in cosmic rays that would result from annihilations of the scalar dark matter candidate of the Inert Doublet Model. We consider three benchmark candidates, all consistent with the WMAP cosmic abundance and existing direct detection experiments, and confront the predictions of the model with the recent PAMELA, ATIC and HESS data. For a light IDM WIMP candidate, M_{DM} = 10 GeV, we argue that the positron and antiproton fluxes are large, but consistent with expected backgrounds, unless there is an enhancement in the local density of dark matter. For an IDM WIMP candidate with M_{DM} = 70 GeV, the contribution is lower than the expected backgrounds unless there is a large boost factor. However, the candidate is enable to explain the excesses observed by the recent experiments. Finally, for an IDM WIMP candidate with M_{DM}=10 TeV, it is possible to fit the PAMELA ...

2009-01-01

199

Drought analysis of Nakdong River Basin based on multivariate stochastic models

The COBE data on cosmic background radiation (CBR) isotropy and spectrum are generally considered to be explicable only in the context of the Big Bang theory and to be confirmation of that theory. However, this data can also be explained by an alternative, non-Big Bang model which hypothesizes an intergalactic radio-absorbing and scattering medium. Dense, force-free magnetic filaments generated by quasars, active galactic nuclei and Herbig-Haro objects can remain stable in the intergalactic medium for many Gy. They will be opaque to radiation with wavelengths longer than 100--400 microns, and essentially transparent to shorter wavelengths. They are thus capable of thermalizing and isotropizing the cosmic background radiation, and of accounting for the observed decrease of radio luminosity of galaxies within increasing distance from earth. A simple, inhomogeneous model of such an absorbing medium can ...

1994-12-31

200

Radionuclide release rates from spent fuel for performance assessment modeling

In this study, drought analysis of annual flows of Jindong, Hyunpoong, and Waekwan stations located at Nakdong River Basins was performed based on multivariate stochastic models. The stochastic models used were multivariate autoregressive model(MAR) and multivariate contemporaneous (MCAR) model. MCAR(1) and MAR(1) models were selected to be appropriate models for these stations based on skewness test of normality, test of uncorrelated residuals, and correlograms of the residual series of each model. The statistics generated by MCAR(1) model and MAR(1) model resembled very closely those computed from historical series. The drought characteristics such as run length, run sum, and run intensity were fairly well reproduced for the various lengths of generated annual flows based on ...

1997-04-30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

201

Investigation of Tumor-Peritoneal Interactions in the Pathogenesis of Peritoneal Metastases using a Novel Ex Vivo Peritoneal Model1

In a scenario of aqueous transport from a high-level radioactive waste repository, the concentration of radionuclides in water in contact with the waste constitutes the source term for transport models, and as such represents a fundamental component of all performance assessment models. Many laboratory experiments have been done to characterize release rates and understand processes influencing radionuclide release rates from irradiated nuclear fuel. Natural analogues of these waste forms have been studied to obtain information regarding the long-term stability of potential waste forms in complex natural systems. This information from diverse sources must be brought together to develop and defend methods used to define source terms for performance assessment models. In this manuscript examples of measures of radionuclide release rates from spent nuclear fuel or analogues of nuclear ...

1994-11-01

202

British Library Electronic Table of Contents (United Kingdom)

BackgroundPeritoneal metastasis occurs in up to 30% of patients with gastric cancer. The aim of this experimental study is to develop and validate a novel ex vivo model of the human peritoneum to better identify factors involved in the development of peritoneal metastasis in order to improve its management and prognosis. MethodsPeritoneal discs harvested from hernia sacs obtained at inguinal hernia surgery were suspended in media using Teflon rings. Viability of the tissue was investigated using MTS assay, light and scanning electron microscopy (LM and SEM) over 72 h. To assess validity of the model, phenotypic changes in tumor cells were investigated. Changes in matrix metalloproteinases (MMP)-2 and -9 activities in HGC and AGS gastric adenocarcinoma cells after co-culture were investigat...

2010-01-01

203

Estrogen and raloxifene improve metaphyseal fracture healing in the early phase of osteoporosis. A new fracture-healing model at the tibia in rat

British Library Electronic Table of Contents (United Kingdom)

Background Fracture healing in osteoporosis is delayed. Quality and speed of fracture healing in osteoporotic fractures are crucial with regard to the outcome of patients. The question arises whether established antiosteoporotic drugs can further improve fracture healing. Materials and methods Osteoporosis manifests predominantly in the metaphyseal bone. Nevertheless, an established metaphyseal fracture model is lacking. A standardized metaphyseal fracture-healing model with stable plate fixation was developed for rat tibiae. The healing process was analyzed by biomechanical, gene expression, and histomorphometric methods in ovariectomized (OVX) and sham-operated rats (SHAM), compared to standardized estrogen (E)- and raloxifene (R)-supplemented diets. Results Estrogen and raloxifene impro...

2010-01-01

204

Cost-effectiveness of a barrier-strengthening moisturizing cream as maintenance therapy vs. no treatment after an initial steroid course in patients with atopic dermatitis in Sweden - with model applications for Denmark, Norway and Finland

British Library Electronic Table of Contents (United Kingdom)

Abstract Background Atopic dermatitis (AD) affects health and quality of life and it has great impact on both health-care costs and costs to the society. Objectives The objective of this study was to develop a model to analyse the cost-effectiveness of a barrier-strengthening moisturizing cream as maintenance therapy compared with no treatment after initial treatment with betamethasone valerate in adult patients with AD in Sweden. A further aim was to apply a similar health-economic analysis for Denmark, Norway and Finland. Methods A Markov simulation model was developed including data from three sources: (i) efficacy data from a randomized controlled trial including patients with moderate AD treated with either a moisturizing cream or no treatment, (ii) resource utilization and quality of...

2010-01-01

205

Cosmological Questions for the European Southern Observatory Very Large Telescope

A Comparison of POSSUM and GPS Models in the Prediction of Post-operative Outcome in Patients Undergoing Oesophago-gastric Cancer Resection

The next decade promises an observational revolution which will change cosmology forever. The precise measurement of the angular anisotropy of the cosmic microwave background should specify to a few percent all of the parameters of the cosmological model which effect astrophysics. The growth of structure will then be determined (but not yet observed) until gravitational collapse becomes highly non-linear and stars, galaxies and active galactic nuclei (AGN) form. These processes are hard to model with basic physics because they are complex and allow a rich variety of expression. Instead observations will determine when the first stars and quasars formed, and how and when galaxies assembled. If we can reconcile the numerous contradictions which characterize the subject today, cosmology will become a mature subject, founded on the agreement between detailed, inclusive and realistic models, which make ...

1996-01-01

206

British Library Electronic Table of Contents (United Kingdom)

Background There is some evidence that a patient?s pre-operative condition influences short-term and long-term post-operative outcomes. The aim of the present study is to compare the physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and modified Glasgow prognostic score (mGPS) models in the prediction of post-operative outcome, both short term and long term, in patients undergoing resection of oesophago-gastric cancer. Patients and Methods Patients who underwent curative resection for oesophago-gastric cancer from January 2005 to May 2009 and who had data to score the POSSUM, P-POSSUM, O-POSSUM and mGPS models were included in the study. Observed morbidity and mortality rates were compared with predicted outcome in different risk groups. Bot...

2011-01-01

207

Mining associations in text in the presence of background knowledge

Heavy metals in Semarang`s urban streams: Spatial distribution and bioindication using the guppy (Lepistes reticulatus)

This paper describes the FACT system for knowledge discovery from text. It discovers associations - patterns of co-occurrence - amongst keywords labeling the items in a collection of textual documents. In addition, FACT is able to use background knowledge about the keywords labeling the documents in its discovery process. FACT takes a query-centered view of knowledge discovery, in which a discovery request is viewed as a query over the implicit set of possible results supported by a collection of documents, and where background knowledge is used to specify constraints on the desired results of this query process. Execution of a knowledge-discovery query is structured so that these back-ground-knowledge constraints can be exploited in the search for possible results. Finally, rather than requiring a user to specify an explicit query expression in the knowledge-discovery query language, FACT presents the user with a simple-to-use graphical ...

1996-12-31

208

Unbiased cut selection for optimal upper limits in neutrino detectors the model rejection potential technique

A field survey on cadmium, lead, copper, and zinc was performed in Semarang, the fifth largest city in Indonesia. Water, sediment, and fish samples were collected from 101 grids of 2 x 2 km. The objectives of the study were (1) to identify the spatial distribution of metals in the sediments of the greater Semarang area, (2) to estimate the background concentrations of the metals present in Semarang, (3) to provide a simple tool for deriving standards for metals in the sediment, and (4) to explore the potential use of the guppy (Lebistes reticulatus) as a bioindicator of urban metal pollution. To map the spatial distribution of the metals, concentrations of each metal in sediment were plotted against the corresponding city coordinate. On the basis of these plots, background concentrations of the metals were estimated. A combined pollution index can be derived thereafter by calculating the difference between metals ...

1996-12-31

209

Reverse engineering databases for knowledge discovery

We present a method for optimising experimental cuts in order to place the strongest constraints (upper limits) on theoretical signal models. The method relies only on signal and background expectations derived from Monte-Carlo simulations, so no bias is introduced by looking at actual data, for instance by setting a limit based on expected signal above the ``last remaining data event.'' After discussing the concept of the ``average upper limit,'' based on the expectation from an ensemble of repeated experiments with no true signal, we show how the best model rejection potential is achieved by optimising the cuts to minimise the ratio of this ``average upper limit'' to the expected signal from the model. As an example, we use this technique to determine the limit sensitivity of kilometre scale neutrino detectors to extra-terrestrial neutrino fluxes from a variety of models, e.g. ...

2003-01-01

210

Latest Observational Constraints on Cardassian Models

Many data mining tools cannot be used directly to analyze the complex sets of relations which are found in large database systems. In our experience, data miners rely on a well-defined data model, or the knowledge of a data expert, to isolate and extract candidate data sets prior to mining the data. For many databases, typically large legacy systems, a reliable data model is often unavailable and access to the data expert can be limited. In this paper we use reverse engineering techniques to infer a model of the database. Reverse engineering a database can be seen as knowledge discovery in its own right and the resulting data model may be made available to data mining tools as background knowledge. In addition, minable data sets can be produced from the inferred data model and analyzed using conventional data mining tools. Our approach reduces the data miner`s ...

1996-12-31

211

The application of utility analysis processes to estimate the impact of training for nuclear maintenance personnel

Constraints on the original Cardassian model and the modified polytropic Cardassian model are examined from the latest derived 397 Type Ia supernova (SNe Ia) data, the size of baryonic acoustic oscillation peak from the Sloan Digital Sky Survey (SDSS), the position of first acoustic peak of the Cosmic Microwave Background radiation (CMB) from the five years Wilkinson Microwave Anisotropy Probe (WMAP), the x-ray gas mass fractions in clusters of galaxies, and the observational H(z) data. In the original Cardassian model with these combined data set, we find $\\Omega_{m0}=0.271^{+0.014}_{-0.014}, n=0.035^{+0.049}_{-0.049}$ at $1 \\sigma$ confidence level. And in the modified polytropic Cardassian model, we find that $\\Omega_{m0}=0.271^{+0.014}_{-0.015}$, $n=-0.091^{+0.331}_{-1.908}$ and $\\beta=0.824^{+0.750}_{-0.622}$ within $1\\sigma$ confidence level. According to these ...

2009-01-01

212

Models comparative study for heat storage in fixed beds; Estudo comparativo de modelos para armazenamento de calor em leitos fixos

The primary objectives of this study were to test two utility analysis models, the Cascio-Ramos Estimate of Performance in Dollars (CREPID) model and Godkewitsch financial utility analysis model and to determine their appropriateness as tools for evaluating training. This study was conducted in conjunction with Philadelphia Electric Company's Nuclear Training Group. Job performance of nuclear maintenance workers was assessed to document the impact of the training program. Assessment of job performance covered six job performance themes. Additionally, front-line nuclear maintenance supervisors were interviewed to determine their perceptions of the nuclear maintenance training. A comparison of supervisor's perceptions and outcomes of the utility analysis models was made to determine the appropriateness of ...

1991-01-01

213

Wind tunnel and numerical study of a small vertical axis wind turbine

This work presents comparative results of a numerical investigation of four possible models for the prediction of thermal performance of fixed bed storage units and their thermal design. These models includes Schumann's model, the radial dispersion model, a model that include both axial heat conduction in the fluid phase and admits thermal gradient in the solids particles and finally a two dimensional single phase model. For each of these models a computer code was written and tested to evaluate the computing time of same data and analyze any other computational problems. The tests of thermal performance included particle size, porosity, particle material, flow rate, inlet temperature and heat losses form tank walls and extremities. Dynamics behaviour of the storage units due to transient ...

1991-07-01

214

British Library Electronic Table of Contents (United Kingdom)

This paper presents a combined experimental and computational study into the aerodynamics and performance of a small scale vertical axis wind turbine (VAWT). Wind tunnel tests were carried out to ascertain overall performance of the turbine and two- and three-dimensional unsteady computational fluid dynamics (CFD) models were generated to help understand the aerodynamics of this performance. Wind tunnel performance results are presented for cases of different wind velocity, tip-speed ratio and solidity as well as rotor blade surface finish. It is shown experimentally that the surface roughness on the turbine rotor blades has a significant effect on performance. Below a critical wind speed (Reynolds number of 30,000) the performance of the turbine is degraded by a smooth rotor surface finis...

2010-01-01

215

Data processing for the mise-a-la-masse survey; Ryuden den`iho tansa no data shori

Modeling and evaluation of externally fired combined cycle using ASPEN

Data processing method was studied for mise-a-la-masse survey. Mise-a-la-masse method using wells as current sources measures resultant ground surface potential difference, and detects underground local resistivity anomaly. To extract resistivity anomaly largely different from surroundings, the anomaly is extracted as difference between the estimated value of regular resistivity structure (background) and potential difference or apparent resistivity. The following three approximations were attempted to estimate the background: the theoretical equation assuming isotropic homogeneous resistivity structure, that assuming horizontal multi-layered structure and the exponential function of distance from linear electrode for apparent resistivity, and these were compared with each other by numerical model experiment. The data processing method which determines the resistivity structure of the background and the ...

1996-10-01

216

Investigation of the impact of electricity rate and mix on optimum green building design

A new performance model of the externally fired combined cycle (EFCC) is implemented in ASPEN (Advanced System for Process ENgineering), a chemical process simulator. The model accounts for interactions within and between approximately a dozen major process areas. The new model is applied to case studies to evaluate the sensitivity of process performance to the ranges of uncertainty in key model inputs such as heat losses, carbon conversion, and air leakage rates, and to illustrate how alternative designs, including steam injection and flue gas desulfurization (FGD), can affect plant thermal efficiency and net power output. The model results suggest that careful attention to the design of the FGD system is needed, especially with respect to reheat, and that steam injection may offer cost savings associated with reducing the size of the steam ...

1997-12-01

217

Underground Test Area Subproject Phase I Data Analysis Task. Volume IV - Hydrologic Parameter Data Documentation Package

The basic principle of the green building philosophy is to design buildings that consider environmental performance. Residential and commercial buildings in Canada consume about 30 per cent of the total secondary energy use and are responsible for approximately 29 per cent of carbon dioxide equivalent greenhouse gas emissions and many other wastes. An optimization model was developed which minimizes life cycle cost and life cycle environmental impact. The model distinguishes different energy sources and incorporates their impacts, such as resource depletion, global warming and acidification. The model also considers design variables such as window type, orientation, building orientation, window-to-wall ratio, wall type and roof type. The model can be used to identify optimum green building designs for given conditions. The model uses expanded cumulative exergy ...

2004-07-01

218

Underground Test Area Subproject Phase I Data Analysis Task. Volume II - Potentiometric Data Document Package

Volume IV of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the hydrologic parameter data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

1996-09-01

219

Predicting the efficiency of activated charcoal for filtering radon

Volume II of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the potentiometric data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

1996-12-01

220

Numerical investigation of carbon dioxide absorption in a falling-film micro-contactor

In order to accurately assess the effectiveness of activated charcoal for the removal of radon from flowing air, a literature survey was performed to identify the models and relevant data that were available. It was found that by modifying the mathematical model of equilibrium stage theory used by Strong and Levins, the output rate of an activated charcoal filter exposed to a step function input in the radon rate at time zero with a given carrier gas flow velocity could be predicted. This paper outlines the modifications made to Strong and Levins's model and presents predictions for the filter output from the modified model.

1993-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

221

Modeling of an electrically rechargeable alkaline zinc-air battery

A rigorous mathematical model is developed to describe chemical absorption of carbon dioxide in a falling-film micro-contactor. Contrary to previous models described in literature, hydrodynamics in both phases is accurately captured by the Navier-Stokes equations. By this means, backmixing effects can be accounted for. Furthermore, the interface position is determined directly using the level-set method. The developed model is validated with experimental data obtained from literature and a good agreement is established. With the validated model, detailed studies are performed to investigate the impact of process parameters.

2010-02-01

222

Comparing Computer Run Time of Building Simulation Programs

A numerical model has been developed to simulate the charging and discharge behaviour of an electrically rechargeable alkaline zinc-air battery. Further a galvanostatic experiment including three charge/discharge cycles has been performed. The cell voltages, the Zn electrode potentials versus a Zn reference, and the O{sub 2} electrode potentials versus a Zn reference calculated with the model are in fairly good agreement with the corresponding experimental data. The model is expected to be useful for zinc-air battery design and for analysis of experimental data. (author)

2003-03-01

223

Thermal model and thermodynamic performance of molten salt cavity receiver

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.

2008-07-23

224

British Library Electronic Table of Contents (United Kingdom)

The design of a global steady-state thermal model of a 100kWt molten salt cavity receiver was developed as part of the key project of the Ministry of Science and Technology of People's Republic of China (MOST). In the design process, the following factors were analyzed: receiver area, heat loss (convective, emissive, reflective and conductive), number of tubes in the receiver panel, tube diameter and receiver surface temperature. The model was also used to calculate the receiver performance of the Sandia National Laboratories' molten salt electric experiment (MSEE). In addition, the thermal performance of the designed molten salt cavity receiver is presented for a fixed outlet flow rate and a fixed output temperature.

2010-01-01

225

RAILPLUG IGNITION SYSTEM FOR ENHANCED ENGINE PERFORMANCE AND REDUCED MAINTENANCE

The Minimal Scale Invariant Extension of the Standard Model

During the first 18 months of this project, four experimental subtasks were to have begun but only one of these was to have been completed. Additionally, five modeling subtasks were scheduled to begin, four of which were to have been completed. We are on schedule for all but one of these subtasks. All four experimental tasks are progressing on schedule. Initial durability tests were completed. The conclusions drawn from this first round of durability tests are being used to design the next set of tests. Initial baseline engine data were acquired and showed that the engine selected for this task behaves as hoped. However, the dyno controller is inadequate. The engine will be moved to another dyno during the near future. The modeling tasks are also progressing well. A model for the dynamic response of the ignition circuit was developed and validated. Two technical papers resulting from this model were ...

2003-09-19

226

Modelling the work flow of a nuclear waste management program

We perform a systematic analysis of an extension of the Standard Model that includes a complex singlet scalar field and is scale invariant at the tree level. We call such a model the Minimal Scale Invariant extension of the Standard Model (MSISM). The tree-level scale invariance of the model is explicitly broken by quantum corrections, which can trigger electroweak symmetry breaking and potentially provide a mechanism for solving the gauge hierarchy problem. Even though the scale invariant Standard Model is not a realistic scenario, the addition of a complex singlet scalar field may result in a perturbative and phenomenologically viable theory. We present a complete classification of the flat directions which may occur in the classical scalar potential of the MSISM. After calculating the one-loop effective potential of the MSISM, we investigate a number of ...

2010-01-01

227

Simulation study of the influence of the ionospheric layer height in the thin layer ionospheric model

In this paper we describe a modelling project to improve a nuclear waste management program in charge of the creation of a new system for the permanent disposal of nuclear waste. SADT (Structural Analysis and Design Technique) is used in order to provide a work-flow description of the functions to be performed by the waste management program. This description is then translated into a number of Coloured Petri Nets (CPN or CP-nets) corresponding to different program functions where additional behavioural inscriptions provide basis for simulation. Each of these CP-nets is simulated to produce timed event charts that are useful for understanding the behaviour of the program functions under different scenarios. Then all the CPN models are linked together to form a single stand-alone application that is useful for validating the interaction and cooperation between the different program functions. A technique for linking ...

1997-03-01

228

British Library Electronic Table of Contents (United Kingdom)

This work aims to contribute to the understanding of the influence of the ionospheric layer height (ILH) on the thin layer ionospheric model (TLIM) used to retrieve ionospheric information from the GNSS observations. Particular attention is paid to the errors caused on the estimation of the vertical total electron content (vTEC) and the GNSS satellites and receivers inter-frequency biases (IFB), by the use of an inappropriate ILH. The work relies upon numerical simulations performed with an empirical model of the Earth?s ionosphere: the model is used to create realistic but controlled ionospheric scenarios and the errors are evaluated after recovering those scenarios with the TLIM. The error assessment is performed in the Central and the northern part of the South American continents, a re...

2011-01-01

229

REALISTIC NON-LINEAR MODEL AND FIELD QUALITY ANALYSIS IN RHIC INTERACTION REGIONS.

Improving Dynamic Load and Generator Response PerformanceTools

The existence of multipole components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. So, a realistic non-linear model is crucial for understanding the beam behavior and to achieve the ultimate performance in RHIC. A procedure is developed to build a non-linear model using the available multipole component data obtained from measurements of RHIC magnets. We first discuss the measurements performed at different stages of manufacturing of the magnets in relation to their current state in RHIC. We then describe the procedure to implement these measurement data into tracking models, including the implementation of the multipole feed down effect due to the beam orbit offset from the magnet center. Finally, the field quality analysis in the RHIC interaction regions (IR) is presented.

2007-06-25

230

Performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS for the 238U (22Ne, 5n)255No reaction

This report is a scoping study to examine research opportunities to improve the accuracy of the system dynamic load and generator models, data and performance assessment tools used by CAISO operations engineers and planning engineers, as well as those used by their counterparts at the California utilities, to establish safe operating margins. Model-based simulations are commonly used to assess the impact of credible contingencies in order to determine system operating limits (path ratings, etc.) to ensure compliance with NERC and WECC reliability requirements. Improved models and a better understanding of the impact of uncertainties in these models will increase the reliability of grid operations by allowing operators to more accurately study system voltage problems and the dynamic stability response of the system to disturbances.

2005-11-01

231

Updated estimates of the proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionising radiation

The performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS was investigated using 255No produced in the 238U(22Ne, 5n)255No reaction. Alpha particles of 255No separated with GARIS and transported by the gas-jet system were measured with a rotating wheel apparatus for ? spectrometry under low background condition. The high gas-jet efficiencies of about 75% were independent of the recoil ranges of 255No in the gas-jet chamber. The present results suggest that the GARIS/gas-jet system is a promising tool for the next-generation superheavy element chemistry: (1) the background radioactivities of unwanted reaction products are strongly suppressed, (2) the intense beam is absent in the gas-jet chamber and hence the high gas-jet efficiency is achieved, and (3) the beam-free condition also allows for investigations of new chemical systems. (author)

2008-08-01

232

Photoproduction of J/{psi} mesons at medium and low elasticities at HERA

The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to ...

2009-12-01

233

Thermal Modeling and Performance Analysis of Interim Dry Storage and Geologic Disposal Facilities for Spent Nuclear Fuel

The first analysis of inelastic J/{psi} meson production in photoproduction (Q{sup 2}<2.5 GeV{sup 2}) of the H1 experiment for the second phase of HERA (HERA II) is presented. The analysis is carried out at low and medium elasticities. The production of heavy quarks (charm, or bottom) is of special interest since the mass of the quarks provides a hard scale for the application of perturbative QCD. The muonic decay channel is used to select the J/{psi} mesons. The data was collected by the H1 detector during the period 2003-2005, and corresponds to an integrated luminosity of 133 pb{sup -1}. However only a subset of this data could be analysed. At the start of HERA II the trigger system was affected by a sizeable background. Then a fault was introduced in the trigger software during the summer 2004 and was only discovered and solved in April 2006. This means that approximately 80 % of the triggered events at medium elasticities and 65 % at low elasticities ...

2007-09-15

234

Radon grab sampling in water by means of radon transfer in activated charcoal collectors

Thermal models are constructed and analyses are performed of aluminum-based spent nuclear fuel (Al-SNF) in interim dry storage and geologic disposal configurations. Two models are developed, referred to as the interim storage model and the codisposal waste package (WP) model. Time-dependent source terms of Al-SNF forms and the defense high-level waste (DHLW) canisters are also developed for thermal performance analysis of the geologic codisposal WP.The interim storage model is a three-dimensional conduction-convection conjugate model to investigate the natural convection cooling of a sealed dry storage canister with vertical orientation in a dry storage vault. The analysis is made for various decay heat sources (equivalent to 25 to 35 kW/m{sup 3}) using various boundary conditions around the canister wall and with ...

2000-07-15

235

Implementation of the Random Forest method for the Imaging Atmospheric Cherenkov Telescope MAGIC

The proposed portable device is suitable for radon surveys in water-bearing strata. It allows a complete transfer in activated charcoal canisters of radon dissolved in water collected with a 0.61 bottle. The detection is performed in laboratory with a low background {gamma}-ray spectrometer utilizing 3{sup x}3{sup N}aI({tau}I) scintillator only after about ten hours. This time is necessary to let radon be uniformly distributed within the activated charcoal.

1999-08-01

236

Expansion Rate Measurements at Moderate Pressure of Nonneutral Electron Plasmas in the Electron Diffusion Gauge (EDG) Experiment

The paper describes an application of the tree classification method Random Forest (RF), as used in the analysis of data from the ground-based gamma telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to be discriminated against a dominating background of hadronic cosmic-ray particles. We describe the application of RF for this gamma/hadron separation. The RF method often shows superior performance in comparison with traditional semi-empirical techniques. Critical issues of the method and its implementation are discussed. An application of the RF method for estimation of a continuous parameter from related variables, rather than discrete classes, is also discussed.

2008-04-11

237

Environmental radiation measurements using TLD in and around AERE, Dhaka. Technical note

Measurements of the expansion rate of pure-electron plasmas have been performed on the Electron Diffusion Gauge (EDG) device at background helium gas pressures in the 5 x 10(superscript -8) Torr to 1 x 10(superscript -5) Torr range, where plasma expansion due to electron-neutral collisions dominates over plasma expansion due to trap asymmetries. It is found that the expansion rate, defined as the time rate of change of the particles' mean-square radius, scales approximately linearly with pressure and inversely as the square of the magnetic field strength in this regime, in agreement with classical predictions.

2001-05-18

238

Development of the EE-1 small community solar thermal power system

The external background radiation level in and around the Atomic Energy Research Establishment (AERE) in Dhaka has been measured. The measurements were performed using lithium fluoride (LiF) thermoluminescence dosemeters (TLD-100) at 32 locations, all one metre above the ground. The annual average dose rate measured in the AERE environs was 1.74+-0.23 mGy.y/sup -1/ in air, based on analysis of thermoluminescence dosemeter data collected from 1982 to 1984.

1986-01-01

239

Condensing curves for a number of mixed-hydrocarbon working fluids

The development status of the EE-1 Small Community Solar Thermal Power Experiment (SCSE Program) is presented. Current activities on the Phase II single module development effort are presented, together with plans for a Phase III 1 MW/sub e/ demonstration plant. A description of the various subsystems and components is given with a brief review of their development background. Latest performance figures are given for a 1 MW/sub e/ plant, based on 56 power modules, each consisting of a 12m parabolic dish concentrator, a cavity receiver, an organic Rankine power conversion subsystem and a ground-mounted solid-state rectifier.

1981-01-01

240

The importance of turbulence modelling in the design of a novel delivery system for a single-belt steel casting process

Condensing curves are presented for a number of two-component mixed hydrocarbon working fluids which are potentially usable in binary geothermal cycles. Performance of geothermal thermodynamic cycles incorporating these fluids has been evaluated under separate cover; two figures summarizing the results of those evaluations have been included here for continuity. The purpose of this report is: first, to document the condensing curves which were used in the mixed fluid cycle analyses, and second, to provide background useful in the preliminary evaluation of heat rejection systems for advanced geothermal electric power plants utilizing mixed hydrocarbon working fluids. Some concluding remarks are presented.

1981-07-01

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241

Development and validation of steam generator models for thermal performance monitoring

In this work, a comprehensive model including heat transfer, fluid flow and solidification was used to evaluate the performance of a novel delivery system for a single-belt steel casting process. This near-net-shape casting, although still in development, is one of the most promising routes for casting of low-carbon steel in large scale. This paper focuses on the performance of a low-Re {kappa}-{epsilon} model that was employed to simulate the three-dimensional turbulent flows fully-coupled with heat transfer and macroscopic solidification. Simulations were run for the intended conditions of caster operation, and the results obtained with the {kappa}-{epsilon} were compared with the results obtained with an ad hoc viscosity model, where the molecular viscosity was boosted 100 times, uniformly throughout the computational domain. A semi-analytical solution was employed for validating ...

2000-01-01

242

Study of Z' {yields} e{sup +}e{sup -} in full simulation with regard to discrimination between models beyond the standard model

The thermal performance monitoring and optimization system TEMPO is developed at the OECD Halden Reactor Project. The system supports staff of nuclear power plants in identification and correction of problems, which cause small decreases in plant efficiency but which may lead to significant economical losses. The system-wide physical model consists of mathematical description of individual components, such as the reactor, the pumps, the heat exchangers, or the turbines, etc. TEMPO code has recently been extended with new steam generator (SG) models. The present paper summarizes the thermal-hydraulic modelling aspects of the vertical and the horizontal SG. The heat balance equations and their solution are shown with the appropriate initial and boundary conditions. The method of the calculation of the pressure losses are also introduced. The vertical SG model is based on a U-tube ...

2003-04-20

243

Optical Modelling of the HFI Instrument on Board the Planck Surveyor

Although experimental results so far agree with predictions of the standard model, it is widely felt to be incomplete. Many prospective theories beyond the standard model predict extra neutral gauge bosons, denoted by Z', which might be light enough to be accessible at the LHC. Observables sensitive to the properties of these extra gauge bosons might be used to discriminate between the different theories beyond the standard model. In the present work several of these observables (total decay width, leptonic cross-section and forward-backward asymmetries) are studied at generation level and with a full simulation in the ATLAS detector. The Z' {yields} e{sup +}e{sup -} decay channel was chosen and 2 values for the mass of Z': 1.5 TeV and 4 TeV. Background is studied as well and it is confirmed that a Z' boson could easily be discovered at the chosen masses. It is shown ...

2004-09-01

244

CAR International. A simple model to determine city street air quality

The PLANCK SURVEYOR is a European Space Agency satellite mission to image the very faint anisotropies in the temperature of the Cosmic Microwave Background (CMB) radiation. Maynooth is actively participating in an international collaboration of scientists involved with the optical design of the High Frequency Instrument (HFI). This paper outlines research which has been undertaken in Maynooth concerned with numerical modelling of the optical characteristics of the multi-frequency array of detectors making up the HFI instrument. In the study the commercial software package ZEMAX was used to model the coupling of the focal plane HFI detectors to the PLANCK telescope. This package is particularly useful in the optical design of PLANCK because of the powerful optimisation features of the software. It is thus possible to readily determine the optimum positioning of the detectors in the focal plane of the telescope. Although the ...

1999-07-01

245

WorId Ocean Circulation Experiment - OceanESIP - NASA

Based on wind tunnel experiments, theoretical considerations and measurements the dispersion model CAR (Calculation of Air pollution from Road traffic) has been developed for determining air quality in city streets. CAR International is a simple parameterized model using readily available input data and calculating annual percentile values and average concentrations close to streets (at the kerb side) for non-reactive air pollutants and NO{sub 2}. Originally the model was set up for the Dutch situation (traffic, meteorology) with a system of fixed parameters. In order to extend its application to other countries the program has been made more flexible and user friendly. User defined system data can now be changed interactively, such as emission factors of passenger cars and trucks, fraction of directly emitted NO{sub 2}, city and regional background concentration, and average regional wind speed. The ...

1995-06-22

246

VAWT performance prediction - Description of a PC-based software

period T. Also shown is the returned chirp from a specular reflector at ...... algorithms is a Brown (1977) model of the return waveform, which assumes a ...... Townsend, W.F., 1980: An initial assessment of the performance achieved by ...

247

Sequential Molecular and Cellular Events during Neoplastic Progression: A Mouse Syngeneic Ovarian Cancer Model1

The Vertical Axis Wind Turbine (VAWT) offers a mechanically and structurally simple method of harnessing the energy of the wind. Fast and accurate predictions of the VAWT performance can be obtained using momentum models. Aerodynamic streamtube models are based on the conservation-of-momentum principle in a quasi-steady flow, by equating the forces of the rotor blades to the change in streamwise momentum through the turbine. An analytical model considering a multi-streamtube system divided into two parts has been developed to determine the aerodynamic blade loads and rotor performance of the Darrieus wind turbine (CARDAA computer code). This so-called double multiple-streamtube (DMS) model uses two constant interference factors in the induced velocities and accounts for vertical variations in the free stream velocity. It has been recently modified to produce an ...

1995-12-31

248

Root Suberin Forms an Extracellular Barrier That Affects Water Relations and Mineral Nutrition in Arabidopsis

AbstractStudies performed to identify early events of ovarian cancer and to establish molecular markers to support early detection and development of chemopreventive regimens have been...Full Text Available

2005-10-01

249

PROBABILISTIC SYSTEMS MODELING AND COST/PERFORMANCE METHODOLOGIES ...

Though central to our understanding of how roots perform their vital function of scavenging water and solutes from the soil, no direct genetic evidence currently exists to support the foundational model...Full Text Available

2009-05-01

250

Materials issues in coal-fired combined cycle power generation systems: laboratory versus plant testing

sidered as produced in one period of time for learning curve purposes. A ...... 61 FORMAT (6X,13,3XTARGET DATE 1,13,1X,A6,' NO LATER THAN',F4.0, ...

251

Functional Analysis of Neurovascular Adaptations to Exercise in the Dentate Gyrus of Young Adult Mice Associated With Cognitive Gain

The successful development of coal-fired combined cycle power generation systems require that all component parts are manufactured from appropriate materials and that these materials give predictable in-service performance. High temperature corrosion resulting from coal-derived particulates, deposition and gaseous species, is potentially life limiting for many components in these systems. Realistic laboratory test methods are outlined for gasifier and gas turbine environments and these have been combined with a materials assessment method based on accurate dimensional metrology. Such tests have allowed the production of models of materials performance as well as accurate comparisons between laboratory and plant derived data. These initial models predict the performance of materials well in the gas turbine environment, but tend to under-predict the damage observed in real gasifier ...

1997-12-31

252

Fourth international seminar on horizontal steam generators.

The discovery that aerobic exercise increases adult hippocampal neurogenesis and can enhance cognitive performance holds promise as a model for regenerative medicine. This study adds two new...Full Text Available

2009-10-01

253

ESR studies of spin-labeled membranes aligned by isopotential spin-dry ultracentrifugation: lipid-protein interactions.

The general objective of the International Seminars of Horizontal Steam Generator Modelling has been the improvement in understanding of realistic thermal hydraulic behaviour of the generators when performing safety analyses for VVER reactors. The main to...

1997-01-01

254

COMPUTER ECONOMICS OF PHYSICAL COAL CLEANING AND FLUE GAS DESULFURIZATION. FINAL REPORT

Electron spin resonance (ESR) studies have been performed on spin-labeled model membranes aligned using the isopotential spin-dry ultracentrifugation (ISDU) method of Clark and Rothschild. This method...Full Text Available

1994-12-01

255

Analysis of Spatio-Temporal Preferences and Encounter Statistics for DTN Performance

The report describes a computer model developed by TVA to simulate the performance and determine the economics of coal cleaning, or coal cleaning combined with flue gas desulfurization (FGD), for power plant emission control processes over a wide range of user-specified condition...

256

Single charged top-pion production at next generation {gamma}{gamma} colliders

Spatio-temporal preferences and encounter statistics provide realistic measures to understand mobile user's behavioral preferences and transfer opportunities in Delay Tolerant Networks (DTNs). The time dependent behavior and periodic reappearances at specific locations can approximate future online presence while encounter statistics can aid to forward the routing decisions. It is theoretically shown that such characteristics heavily affect the performance of routing protocols. Therefore, mobility models demonstrating such characteristics are also expected to show identical routing performance. However, we argue models despite capturing these properties deviate from their expected routing performance. We use realistic traces to validate this observation on two mobility models. Our empirical results for epidemic routing show those models' ...

2010-01-01

257

Trends in adrenalectomy: a recent national review

The future e{sup +}e{sup -} linear colliders can also operate in the e{gamma} or {gamma}{gamma} modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process {gamma}{gamma} {yields} tb-bar{pi}{sub t}{sup -}. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode {pi}{sub t}{sup -} {yields} bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in {gamma}{gamma} mode at the TeV energy scale.

2008-09-15

258

British Library Electronic Table of Contents (United Kingdom)

Background Adrenalectomy remains the definitive therapy for most adrenal neoplasms. Introduced in the 1990s, laparoscopic adrenalectomy is reported to have lower associated morbidity and mortality. This study aimed to evaluate national adrenalectomy trends, including major postoperative complications and perioperative mortality. Methods The Nationwide Inpatient Sample was queried to identify all adrenalectomies performed during 1998?2006. Univariate and multivariate logistic regression were performed, with adjustments for patient age, sex, comorbidities, indication, year of surgery, laparoscopy, hospital teaching status, and hospital volume. Annual incidence, major in-hospital postoperative complications, and in-hospital mortality were evaluated. Results Using weighted national estimate, 4...

2010-01-01

259

Post-operative hilotherapy in SMAS-based facelift surgery: A prospective, randomised, controlled trial

British Library Electronic Table of Contents (United Kingdom)

Background: Ecchymosis, oedema, haematoma and pain after SMAS-based facelift surgery are all the direct result of the physical trauma of surgery and subsequent inflammatory response. Hilotherapy is a novel form of cryotherapy that purports to minimise these events through single-use face masks circulating cooled, sterile water. This study was performed to assess the validity of Hilotherapy in this population of patients. Methods: Over 14 weeks fifty consecutive patients were randomised to post-operative facial cooling with Hilotherapy or management with standard dressings alone, while fifteen subsequent, consecutive patients were randomised to cooling of one side of the face but not the other. Assessment of ecchymosis, oedema, haematoma and pain was performed independently by clinical staf...

2011-01-01

260

Comparison of laparoscopic transabdominal lateral versus posterior retroperitoneal adrenalectomy

British Library Electronic Table of Contents (United Kingdom)

Background For the past 14 years, we have been performing laparoscopic adrenalectomy via the lateral transabdominal as well as the posterior retroperitoneal approach. The aim of this study is to describe patient selection criteria for each approach with comparison of perioperative outcomes. Methods In patients with smaller tumors, low body mass index (BMI), history of previous abdominal operations, appropriate body habitus, and bilateral pathology, we have performed preferentially the posterior approach. Data regarding clinical pathology, tumor size, BMI, estimated blood loss (EBL), operating time (OT), morbidity, mortality, and duration of stay were analyzed retrospectively. Data are expressed as mean +- standard error of the mean (SEM). Results One hundred seventy-two laparoscopic adrena...

2009-01-01

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261

Comparative environmental performance of semi-trailer load boxes for grain transport made of different materials

British Library Electronic Table of Contents (United Kingdom)

Background, aim, and scope Semi-trailers with load boxes are the most important mode of grain transport by land in the world. Load boxes can be produced with different materials such as: wood, steel, and synthetic material. They are responsible for effectiveness retention and quality of grains during the transport. Among the main aspects to be considered and valued when selecting materials for load boxes are the final mass of the semi-trailer, loss of grains, and mechanical properties. Environmental performance is another important aspect to be taken into account for developing and selecting new materials in this kind of application. This study presents a comparative environmental evaluation of load boxes built from two different materials (a wood panel and a three-layer synthetic (TLS) pa...

2010-01-01

262

Adrenal incidentaloma: Does an adequate workup rule out surprises?

British Library Electronic Table of Contents (United Kingdom)

Background Adrenal incidentaloma remains a diagnostic challenge. Despite well-established management guidelines, the long-term results of following these guidelines are unknown. We sought to determine how accurately these guidelines identify functioning incidentalomas and how often these guidelines result in adrenalectomy for benign tumors. Methods We catalogued adrenal incidentalomas from a retrospective review of 500 consecutive adrenalectomies at a single institution. The outcome measures studied were patient demographics, preoperative biochemical analysis, imaging characteristics, tumor size, type of operation performed, and postoperative histologic diagnosis. Results Eighty-one of the 500 adrenalectomies performed were for incidentalomas. Size was the only significant characteristic t...

2010-01-01

263

A high-performance liquid chromatography-based radiometric assay for sucrose-phosphate synthase and other UDP-glucose requiring enzymes

Thermal performance and design of a solid particle cavity receiver

A method for product analysis that eliminates a problematic step in the radiometric sucrose-phosphate synthase assay is described. The method uses chromatography on a boronate-derivatized high-performance liquid chromatography column to separate the labeled product, (14C)sucrose phosphate, from unreacted uridine 5{prime}-diphosphate-(14C)glucose (UDP-Glc). Direct separation of these compounds eliminates the need for treatment of the reaction mixtures with alkaline phosphatase, thereby avoiding the problem of high background caused by contaminating phosphodiesterase activity in alkaline phosphatase preparations. The method presented in this paper can be applied to many UDP-Glc requiring enzymes; here the authors show its use for determining the activities of sucrose-phosphate synthase, sucrose synthase, and uridine diphosphate-glucose pyrophosphorylase in plant extracts.

1991-05-01

264

A unified model of combined energy systems with different cycle modes and its optimum performance characteristics

A model for energy transport in a solid particle cavity receiver is developed and applied to the design and analysis of a receiver for the Central Receiver Test Facility (CRTF), Albuquerque, New Mexico. The model gives thermal performance results - including particle temperatures, cavity efficiencies, and wall temperatures - which directly affect the economic and technical feasibility of a solid particle receiver. In addition, design criteria relevant to the configuration of a solid particle cavity receiver are developed. Results for CRTF indicate that at design conditions particle temperatures will exceed 1200/sup 0/K with cavity efficiencies on the order of 75%.

1985-04-01

265

Pair production of charged top-pions in the $\\gamma\\gamma$ collisions at the ILC

A unified model is presented for a class of combined energy systems, in which the systems mainly consist of a heat engine, a combustor and a counter-flow heat exchanger and the heat engine in the systems may have different thermodynamic cycle modes such as the Brayton cycle, Carnot cycle, Stirling cycle, Ericsson cycle, and so on. Not only the irreversibilities of the heat leak and finite-rate heat transfer but also the different cycle modes of the heat engine are considered in the model. On the basis of Newton's law, expressions for the overall efficiency and power output of the combined energy system with an irreversible Brayton cycle are derived. The maximum overall efficiency and power output and other relevant parameters are calculated. The general characteristic curves of the system are presented for some given parameters. Several interesting cases are discussed in detail. The results obtained here are very general and ...

2009-06-15

266

Chargino production at high energy {gamma}{gamma} colliders with polarized beams

The top-color assisted technicolor (TC2) mode predicts the existence of a pair of charged top-pions $\\pi^{\\pm}_t$. In this paper, we study the production of the charged top-pions pair $\\pi^{\\pm}_t$ at next generation $\\gamma\\gamma$ colliders. The results show that the production rates can reach the level of $10^2$ fb with reasonable parameter space. With a large number of events and the clean background, the charged top-pion should be observable at the $\\gamma\\gamma$ colliders. Therefore, our studies can help us to search for charged top-pion, and furthermore, to test the TC2 model.

2011-01-01

267

Chargino production at high energy #gamma##gamma# colliders with polarized beams

We investigate the chargino production process {gamma}{gamma} {yields} (W-tilde){sup +}(W-tilde){sup -} at high energy {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy {gamma} beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background {gamma}{gamma} {yields} W{sup +}W{sup -}. (author).

1995-05-01

268

Biogas supply to the natural gas supply grid. Study; Einspeisung von Biogas in das Erdgasnetz. Studie

We investigate the chargino production process #gamma##gamma# #-># (W-tilde)"+(W-tilde)"- at high energy #gamma##gamma# colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy #gamma# beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background #gamma##gamma# #-># W"+W"-. (author).

1995-05-01

269

Anomalous single production of fourth generation $t'$ quarks at ILC and CLIC

Biogas supply to the public gas grid is a new option discussed in the most recent publication of Fachagentur Nachwachsende Rohstoffe (FNR) e.V. The biogas is purified, upgraded to natural gas quality and fed into an existing gas grid. Once there, it can be transported across long distances and also used for electric power generation at the consumer side. The study investigates inhowfar and in what instances this method is feasible and promising. It discusses the technical background and the regional potential of biogas. Seven model biogas systems are presented as examples. (orig.)

2006-07-01

270

Predictive Capability Maturity Model for computational modeling and simulation.

We present a detailed study of the anomalous single fourth generation $t'$ quark production within the dominant Standard Model(SM) decay modes at future $e^+e^-$ colliders. We calculate the signal and background cross sections in the mass range 300-800 GeV. We also discuss the limits of $t'q\\gamma$ and $t'qZ$ ($q=u,c$) anomalous couplings as well as values of attainable integrated luminosity for 3$\\sigma$ observation limit.

2011-01-01

271

A critical look at the kinetic models of thermoluminescence-II. Non-first order kinetics

The Predictive Capability Maturity Model (PCMM) is a new model that can be used to assess the level of maturity of computational modeling and simulation (M&S) efforts. The development of the model is based on both the authors experience and their analysis of similar investigations in the past. The perspective taken in this report is one of judging the usefulness of a predictive capability that relies on the numerical solution to partial differential equations to better inform and improve decision making. The review of past investigations, such as the Software Engineering Institute's Capability Maturity Model Integration and the National Aeronautics and Space Administration and Department of Defense Technology Readiness Levels, indicates that a more restricted, more interpretable method is needed to assess the maturity of an M&S effort. The PCMM addresses six ...

2007-10-01

272

Inhalation Exposure Input Parameters for the Biosphere Model

Non-first order (FO) kinetics models are of three types; second order (SO), general order (GO) and mixed order (MO). It is shown that all three of these have constraints in their energy level schemes and their applicable parameter values. In nature such restrictions are not expected to exist. The thermoluminescence (TL) glow peaks produced by these models shift their position and change their shape as the trap occupancies change. Such characteristics are very unlike those found in samples of real materials. In these models, in general, retrapping predominates over recombination. It is shown that the quasi-equilibrium (QE) assumption implied in the derivation of the TL equation of these models is quite valid, thus disproving earlier workers' conclusion that QE cannot be held under retrapping dominant conditions. However notwithstanding their validity, they suffer from the shortcomings as stated ...

2005-01-07

273

Practical application of economic well-performance criteria to the optimization of fracturing treatment design

This analysis is one of 10 reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. Inhalation Exposure Input Parameters for the Biosphere Model is one of five reports ...

2004-09-10

274

The implications of episodic nonequilibrium fracture-matrix flow on site suitability and total system performance

Low-permeability reservoirs are currently being propped with sand, resin-coated sand, intermediate-density proppants, and bauxite. This wide range of proppant cost and performance has resulted in a proliferation of proppant selection models. Initially, a rather vague relationship between well depth and proppant strength dictated the choice of proppant. More recently, computerized models of varying complexity have become available that use net-present-value (NPV) calculations. The input is based on the operator's performance goals for each well and on specific reservoir properties. Simpler, noncomputerized approaches also being used include cost/performance comparisons and nomographs. Each type of model, including several of the computerized models, will be examined. By use of these models and NPV calculations, ...

1988-02-01

275

What can we learn about extragalactic radio jets from X-ray data?

We apply our work on fracture- and matrix-dominated flow to develop a conceptual model of hydrological flow processes in the unsaturated zone at Yucca Mountain. The possibility of fracture-dominated flow is discussed, and various deductions are made on its impact on natural and total system performance, site characterization activities, and site suitability determination.

1992-04-12

276

Prolonged Blood Storage Does Not Effect Survival in an Animal Model of Hemorrhagic Shock

We review the current status of resolved X-ray emission associated with extragalactic radio jets and hotspots. The primary question for any particular jet is to decide if the X-rays come from the synchrotron process or from inverse Compton scattering. There is considerable evidence supporting synchrotron emission for knots in the jets of FRI galaxies. For FRII terminal hotspots detected in the X-ray band, synchrotron self-Compton emission continues to provide viable models with one possible exception (so far). Inverse Compton scattering on photons of the cosmic microwave background is indicated for a few powerful jets, and is expected to be an important contributor if not the dominating mechanism for higher redshift objects. The application of a model generally yields physical parameters and in many cases, these include the Doppler boosting factor.

2003-01-01

277

British Library Electronic Table of Contents (United Kingdom)

Summary Background: Red blood cell (RBC) transfusion in hemorrhagic shock is life saving. However, several clinical trials have shown that blood transfusion in the critically ill patient might be associated with adverse outcomes. Furthermore, an association between prolonged blood storage and adverse effects of RBC transfusion has been postulated. The aim of this study is to examine the effect of blood storage time on resuscitation outcome, in an animal model of hemorrhagic shock. Methods: 20 Wistar rats were phlebotomized in order to induce reversible hemorrhagic shock. Half of them were resuscitated with blood stored for a short period of time (4 days), and the other ones were resuscitated with blood stored for a prolonged time (14 days). Blood samples for hemoglobin, pH, lactate, bicarb...

2011-01-01

278

Laser Photobiomodulation of Wound Healing: A Review of Experimental Studies in Mouse and Rat Animal Models

British Library Electronic Table of Contents (United Kingdom)

Abstract Objectives: This investigation reviewed experimental studies of laser irradiation of wound healing in mice and rats published from 2003 to August 2008, respectively, to assess putative stimulatory effects of this treatment. Background: Animal models, including rodents, attempt to reflect human wound healing and associated problems such as dehiscence, ischemia, ulceration, infection, and scarring. They have played a key role in furthering understanding of underlying mechanisms involved in impaired wound healing, and in testing new therapeutic strategies including laser irradiation. Method: Original research papers investigating effects of laser or monochromatic light therapy on wound healing in mice and rats and published from January 2003 to August 2008 were retrieved from library...

2010-01-01

279

Integration of Tissue-engineered Cartilage With Host Cartilage: An In Vitro Model

British Library Electronic Table of Contents (United Kingdom)

Background We developed a tissue-engineered biphasic cartilage bone substitute construct which has been shown to integrate with host cartilage and differs from autologous osteochondral transfer in which integration with host cartilage does not occur. Questions/purposes (1) Develop a reproducible in vitro model to study the mechanisms regulating tissue-engineered cartilage integration with host cartilage, (2) compare the integrative properties of tissue-engineered cartilage with autologous cartilage and (3) determine if chondrocytes from the in-vitro formed cartilage migrate across the integration site. Methods A biphasic construct was placed into host bovine osteochondral explant and cultured for up to 8 weeks (n?=?6 at each time point). Autologous osteochondral implants served as controls...

2011-01-01

280

Estimating personal costs incurred by a woman participating in mammography screening in the National Breast and Cervical Cancer Early Detection Program

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND.The National Breast and Cervical Cancer Early Detection Program (NBCCEDP) covers the direct clinical costs of breast and cervical cancer screening and diagnostic follow-up for medically underserved, low-income women. Personal costs are not covered. In this report, the authors estimated personal costs per woman participating in NBCCEDP mammography screening by race/ethnicity and also estimated lifetime personal costs (ages 50-74 years).METHODS.A decision analysis model was constructed and parameterized by using empiric data from a retrospective cohort survey of mammography rescreening among women ages 50 years to 64 years who participated in the NBCCEDP. Data from 1870 women were collected from 1999 to 2000. The model simulated the flow of resources incurred by a woman participat...

2008-01-01

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281

Closed-form solutions for some metric perturbations from a closed Friedmann model and the distortion of the universe

Performance testing of the Ford/GE Second Generation Single-Shaft Electric Propulsion (ETX-II) System

We consider perturbations of a particular type (homogeneous of Bianchi type IX) from a closed Friedmann-Robertson-Walker model. By considering a perfect fluid, we obtain closed-form solutions for the perturbations in three interesting cases: stiff matter, radiation, and dust. As a cosmological application, we obtain an upper limit on the relative shear, (sigma/theta)_0 < b/sub 0exp/, if the microwave background radiation was last scattered at a mean red-shift element of [7,10"3] and the density parameter is #OMEGA# element of (1,10), where b/sub 0exp/ is the relative root-mean-square deviation of the temperature over the whole sky.

282

Performance optimization of the humidification?dehumidification desalination process using mathematical programming

System-level-operational testing of the ETX-II test-bed electric vehicle is described and the results discussed. Because the traction battery is a major factor in the performance of an electric vehicle, previously reported work on the sodium-sulfur battery designed for use with the ETX-II is reviewed in detail. Chassis dynamometer performance of the test-bed vehicle met or exceeded design goals and compared reasonably well with SIMPLEV computer modeling results. Areas are identified wherein further work is needed to establish a firmer basis for comparison of the simulation and the observed results.

1993-06-01

283

British Library Electronic Table of Contents (United Kingdom)

In this paper the humidification?dehumidification desalination process is studied and its performance optimized using mathematical programming. An advantage of this method is consideration of the simultaneous effect of various parameters on process performance. An NLP system model is solved for three objective functions: minimization of specific thermal energy consumption, maximization of productivity and maximization of condenser heat recovery. The solutions have been improved especially from a productivity point of view in comparison with previous studies. The productivity objective function leads to the best solution if there is no limitation for the humidifier inlet water temperature. Otherwise, the specific energy objective function seems to be better than others. In the next step the...

2009-01-01

284

Humidification dehumidification desalination process: Design and performance evaluation

British Library Electronic Table of Contents (United Kingdom)

This paper focuses on the design and modeling of the humidification dehumidification desalination (HDH) process. The process is only found on experimental or very small pilot scale. Literature studies are rather limited and it includes a number of experimental investigations, performance evaluation, and measurements of the heat and mass transfer coefficients. This study includes useful and new data on the evaluation of the heat transfer coefficient of the humid air stream in the condenser unit. The analysis develops a correlation for the heat transfer coefficient for the humid air stream as a function of the Reynolds and Prandtl numbers. Also, detailed evaluation of the system performance is presented as a function of the system temperatures and the inlet relative humidity of the air strea...

2008-01-01

285

Design and experimental investigation of a decentralized GA-optimized neuro-fuzzy power system stabilizer

Development of the integrated environmental control model. Technical progress report, [October 1--December 31, 1992

The aim of this research is the design and implementation of a decentralized power system stabilizer (PSS) capable of performing well for a wide range of variations in system parameters and/or loading conditions. The framework of the design is based on Fuzzy Logic Control (FLC). In particular, the neuro-fuzzy control rules are derived from training three classical PSSs; each is tuned using GA so as to perform optimally at one operating point. The effectiveness and robustness of the designed stabilizer, after implementing it to the laboratory model, is investigated. The results of real-time implementation prove that the proposed PSS offers a superior performance in comparison with the conventional stabilizer. (author)

2010-09-15

286

Development of the integrated environmental control model

In its current configuration, the IECM provides a capability to model various conventional and advanced processes for controlling air pollutant emissions from coalfired power plants before, during, or after combustion. The principal purpose of the model is to calculate the performance, emissions, and cost of power Plant configurations employing alternative environmental control methods. The model consists of various control technology modules, which may be integrated into a complete utility plant in any desired combination. in conuwt to conventional deterministic models, the IECM offers the unique capability to assign probabilistic values to all model input parameters, and to obtain probabilistic outputs in the form of cumulative distribution functions indicating the likelihood of different costs and performance results. The most recent ...

1993-01-01

287

Characteristics of the Receptor for the Biosphere Model

In its current configuration, the IECM provides a capability to model various conventional and advanced processes for controlling air pollutant emissions from coalfired power plants before, during, or after combustion. The principal purpose of the model is to calculate the performance, emissions, and cost of power Plant configurations employing alternative environmental control methods. The model consists of various control technology modules, which may be integrated into a complete utility plant in any desired combination. in conuwt to conventional deterministic models, the IECM offers the unique capability to assign probabilistic values to all model input parameters, and to obtain probabilistic outputs in the form of cumulative distribution functions indicating the likelihood of different costs and performance results. The most recent ...

1993-01-01

288

Survey of the core helium flash with dynamic convection

This analysis report is one of a series of technical reports that document the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. This report is one of the five biosphere reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model, as well as the mathematical model and its input parameters. Figure 1-1 is a graphical representation of the documentation hierarchy for the ERMYN. This figure shows relationships among the products (i.e., scientific analyses and model reports) developed for biosphere modeling and biosphere abstraction ...

2004-09-09

289

Simulation of a geothermal heat pump with non-azeotropic mixture

Calculations have been performed to study the dependence on model parameters of convectively heating the region interior to the core convection zone for core helium flash models. We find that interior heating always occurs on a time scale significantly shorter than the evolutionary time scale even at the peak of the flash.

1983-06-15

290

Physical modeling of flow control device test in intake structure

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)

2003-08-01

291

Optical and statistical model calculation of the americium 242m capture cross section

The seawater in the intake structure flows into the large pump to with draw excess heat from the turbine steam condenser. In the intake structure of a nuclear power plant, undesirable pump operating characteristics such as vortices, impeller damages and non-uniform pump-approach flow around the pump bells take place frequently due to poorly-arranged intake geometry. In this study, physical modeling test was performed to predict the hydraulic phenomenon, and proposed flow control devices.

2000-05-01

292

Horizontal steam generator modelling with CATHARE; validation of several nodalization schemes on plant data

The capture cross sections of Am 242m can be deduced from resonances analysis at low energy and computed with theoretical models at high energy. In this work, a coherent set of cross sections which reproduced the experimental values of the fission cross sections is computed. These calculations were performed for an energy of the incoming neutron between 1 keV and 1 MeV.

293

Horizontal steam generator modelling with CATHARE; validation of several nodalization schemes on plant data

The results of the development work to improve the horizontal steam generator modelling using the CATHARE code as well as the results of the steady-state and the steam-line break calculations are presented. Also the results of the steady-state calculations are compared to the measurements performed in operating VVER power plants. (9 refs., 6 figs., 2 tabs.).

1993-12-31

294

Fuel Cell Power Model Elucidates Life-Cycle Costs for Fuel Cell-Based Combined Heat, Hydrogen, and Power (CHHP) Production Systems (Fact Sheet)

The results of the development work to improve the horizontal steam generator modelling using the CATHARE code as well as the results of the steady-state and the steam-line break calculations are presented. Also the results of the steady-state calculations are compared to the measurements performed in operating VVER power plants. (9 refs., 6 figs., 2 tabs.).

1992-09-29

295

Computer modeling in the design and evaluation of electric and hybrid vehicles

This fact sheet describes NREL's accomplishments in accurately modeling costs for fuel cell-based combined heat, hydrogen, and power systems. Work was performed by NREL's Hydrogen Technologies and Systems Center.

2010-11-01

296

Modelling the effects of measured anode triple-phase boundary densities on the performance of micro-tubular hollow fiber SOFCs

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.

1996-08-16

297

British Library Electronic Table of Contents (United Kingdom)

The percolated or active triple phase boundary (TPB) length per unit volume of Ni-YSZ anode hollow fibers (HFs) containing 60wt.% initial NiO and a spatially varying microstructure were measured using a focused ion beam (FIB)-SEM technique. The measured values of contiguous TPB density were interfaced with a 2-D distributed finite element model of a hollow fiber solid oxide fuel cell. The model was applied to simultaneously solve the ionic and electronic charge balances in the electrodes, which were modelled as overlying continuum materials with effective electronic and ionic conductivities. The model was used to predict the effects of anode microstructure on the distribution of current density, and anode activation polarization. Active TPB lengths of 2.63-8.63 m^-^2 were measured for the ...

2011-01-01

298

Electrochemistry Modeling of Proton Exchange Membrane (PEM) Water Electrolysis for Hydrogen Production

Economic analysis of Darrieus vertical axis wind turbine systems for the generation of utility grid electrical power. Volume II. Economic optimization model

An electrochemistry model was developed to analyse the J-V characteristics of a Proton Exchange Membrane (PEM) water electrolyzer for hydrogen production. The Butler-Volmer equation and water transport characteristics through electrolyte membrane were employed to simulate the electrode activation over-potential and membrane ohmic over-potential, respectively. The modeling results are found to agree reasonably well with experimental data published in the literature. The parametric simulations show that the ohmic over-potential is relatively small with typical water content in the membrane. Compared with the cathode over-potential, the anode over-potential is more significant and constitutes the major source of voltage loss. The high anode over-potential is due to the relatively slow oxidation kinetics, which is related to anode material property and microstructure. This model can be integrated with a photovoltaic or wind ...

2006-06-13

299

Analysis of the bullwhip effect in multi-product, multi-stage supply chain systems-a simulation approach

This report is part of a four-volume study of Darrieus vertical axis wind turbine (VAWT) economics. This volume describes a computer model of VAWT cost and performance factors useful for system design and optimization. The content and limitations of the model are outlined. Output data are presented to demonstrate selection of optima and to indicate sensitivity of energy cost to design parameter variations. Optimized specifications generated by this model for six point designs are summarized. These designs subsequently receive a detailed economic analysis discussed in Volume IV. An appendix is included with a FORTRAN IV listing of the model and a description of the input/output characteristics.

1979-08-01

300

British Library Electronic Table of Contents (United Kingdom)

This research aims to develop a simulation approach based on system dynamics modelling (SDM) and adaptive network based fuzzy inference system (ANFIS) for quantifying and reducing the bullwhip effect in a multi-product, multi-stage supply chain. The proposed model is comprised of three groups of variables influencing the bullwhip effect, namely the structure of a supply chain network, supply chain contributions (ordering process in regular situation or when a supplier has a promotion or shortage gaming) and supply chain performances (the number of defects and ordering lead time). As a result, a two layer simulation model is developed with three generic models. The flexibility of this proposed approach is its ability to model various types of ordering policies which are basic inventory poli...

2010-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

301

A specification test for univariate and multivariate proportional hazards models.

A finite element based model for electrochemical discharge machining in discharge regime

This paper applies White's (1982, Econometrica 50, 1-25) information matrix (IM) test for correct model specification to proportional hazards models of univariate and multivariate censored survival data. Several alternative estimators of the test statistic are presented and their size performance examined. White also suggested an estimator of the parameter covariance matrix that was robust to certain forms of model misspecification. This has been subsequently proposed by others (e.g., Royall, 1986, International Statistical Review 54, 221-226) and applied by Huster, Brookmeyer, and Self (1989, Biometrics 45, 145-156) as part of an independence working model (IWM) approach to multivariate censored survival data. We illustrate how the IM test can be used for both univariate data and as part of the IWM approach to multivariate data. PMID:8117901

1993-12-01

302

British Library Electronic Table of Contents (United Kingdom)

Electrochemical discharge machining (ECDM) is a promising hybrid process for high-performance machining of non-conductive glass. ECDM drilling has been found to have different characteristics and material removal mechanisms in discharge regime (less than 300??m in depth) and hydrodynamic regime (more than 300??m in depth); however, these regimes are never separately modeled in existing ECDM models, which leads to large prediction error, especially at low applied voltages and high machining depths. Until now, no model is particularly designed for discharge regime, where most material is removed. In this paper, a finite element based model for ECDM drilling in discharge regime is presented. Material removal subjected to a single spark was simulated using finite element method. The drilling d...

2011-01-01

303

The dosimetric verification of a pencil beam based treatment planning system

Frontiers of Nuclear Astrophysics

A new three-dimensional treatment planning system (TPS) based on convolution/superposition algorithms (TMS-Radix from HELAX AB, Uppsala, Sweden) was recently installed at the University Hospital in Lund. The purpose of the present study was to design a quality assurance and acceptance testing programme to meet the specific characteristics of this convolution model. The model is based on parametrization of a non-measurable quantity - the polyenergetic pencil beam. However, the verification of the treatment planning model is still dependent on numerous comparisons of measured depth-doses and dose profiles. The test programme was divided in two basic parts: (i) model implementation and beam data consistency and (ii) model performance and limitations in special situations. The first part was scheduled for all photon beam qualities available before they could be used ...

304

Development of a computerized portal verification scheme for pelvic treatment fields

The main goals of nuclear astrophysics have been to probe the interiors of stars, stellar explosions, the early moments of cosmic expansion, and the formation and evolution of galaxies and cosmic structure by measurement and application of the relevant nuclear physics. The approach to these goals have generally been from three directions: 1) Careful measurements of the relevant nuclear reactions; 2) Detailed computer models of the relevant astrophysical environments; and 3) Observations of the relevant terrestrial and extra-terrestrial atomic and isotopic abundances. These approaches provide not only insight into the formation and evolution of the elements, but are also pillars upon which a variety of cosmological models as well as models for physics beyond the standard model of particle physics can stand or fall. At present there is a very exciting frontier on all three of these approaches. The ...

2008-06-01

305

Yeast as a Model System to Study Tau Biology

Purpose/Objective: At present, treatment verification between portal and reference images is performed based on manually-identified features by radiation oncologist, which is both time-consuming and potentially error-prone. There is a demand for the computerized verification procedure in clinical application. The purpose of this study is to develop a computerized portal verification scheme for pelvic treatment fields. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature matching between reference and portal images and quantitative evaluation of patient setup. Electronic portal images with a matrix size of 256 x 256 and 12 bit gray levels were acquired using a liquid matrix electronic portal imaging device. Simulation images were acquired by digitizing simulation films using a TV camera into images with 256 x 256 matrix and 8 bit gray levels. Initially a Canny edge detector is applied to identify the ...

1996-09-01

306

Synthesis of model compounds for coal liquification research

Hyperphosphorylated and aggregated human protein tau constitutes a hallmark of a multitude of neurodegenerative diseases called tauopathies, exemplified by Alzheimer's disease. In spite of an enormous amount of research performed on tau biology, several crucial questions concerning the mechanisms of tau toxicity remain unanswered. In this paper we will highlight some of the processes involved in tau biology and pathology, focusing on tau phosphorylation and the interplay with oxidative stress. In addition, we will introduce the development of a human tau-expressing yeast model, and discuss some crucial results obtained in this model, highlighting its potential in the elucidation of cellular processes leading to tau toxicity.

2011-04-06

307

Preliminary reactor cavity melt dispersal model for direct containment heating scenarios

Research continued on the synthesis of model compounds for coal liquefaction research. This report covers the actual laboratory investigation performed during the reporting period in order to attain the stated objective of the project, viz, the synthesis of a model compound containing tetrahydronaphthalene, naphthalene and phenyl moieties linked by methylene, ethylene and ether bonds. The overall synthetic approach aimed at obtaining the end product has been broken down into three major steps that involve the synthesis of three key reactive intermediates. These are: (1) 3,5-dimethyl-5-bromobenzyl chloride, (2) 1-chloromethylene-2-hydroxytetralin and (3) 2-chloromethylene-1-hydroxynaphthalene.

1990-10-08

308

Phase-space analysis of interacting phantom cosmology

This paper presents the results of a series of experiments performed to study the effect of initial pressure vessel conditions on the extent of melt dispersal from scaled reactor cavities and describes progress in development of a mathematical model which is designed to predict the melt mass dispersed from reactor cavities as a function of reactor vessel initial conditions and on the vessel breach area. The model, which is being developed to also characterize the heat transfer and chemical reaction phenomena which would take place within the reactor cavity, is designed to be incorporated into a lumped-parameter containment analysis computer code.

1989-01-01

309

Local wind patterns for modelling renewable energy systems by means of cluster analysis techniques

We perform a detailed phase-space analysis of various phantom cosmological models, where the dark energy sector interacts with the dark matter one. We examine whether there exist late-time scaling attractors, corresponding to an accelerating universe and possessing dark energy and dark matter densities of the same order. We find that all the examined models, although accepting stable late-time accelerated solutions, cannot alleviate the coincidence problem, unless one imposes a form of fine-tuning in the model parameters. It seems that interacting phantom cosmology cannot fulfill the basic requirement that led to its construction.

2008-01-01

310

LES benchmark study of high cycle temperature fluctuations caused by thermal striping in a mixing tee

A method based on cluster analysis techniques is proposed in order to obtain representative local wind patterns. Modeling renewable energy systems, in an accurate way which strongly depends on wind loads, requires reliable data to analyze their response and evaluate their performance. Otherwise poor agreement with the models may be obtained. In a case study for La Paz, Baja California Sur, Mexico, four different wind patterns were obtained from a one-year data set recorded at 10-min intervals. (author)

2002-02-01

311

Heat generation of magneto-rheological fluid dampers

Thermal striping is identified as one of the causes of thermal fatigue failure in nuclear power plants. Numerical studies of thermal striping require three-dimensional, unsteady turbulent modeling that resolves both large and small-scale turbulent motions. Benchmark studies were carried out using the LES turbulence model solved by the commercial CFD code FLUENT. Two types of mixing tee configurations were modeled to evaluate the performance of the CFD code. The simulation results presented in normalized average temperature and normalized fluctuating temperatures are in good agreement with measurements.

2006-02-15

312

Development of regulatory techniques for operational performance evaluation of nuclear power plants

This study presents a theoretical analysis of heat generation and dissipation of field-controllable magneto-rheological fluid (MRF) shock absorbers. Since MRF dampers are energy- dissipating devices, the issues of heat generation and dissipation are important in predicting their performance. A theoretical model is developed based on Bingham plastic model to estimate temperature history of the MRF dampers. The governing equation includes the MRF viscosity as a function of the temperature. The numerical solutions are compared with experimental results in order to validate the accuracy of the model, and excellent agreements are obtained.

2000-04-01

313

Computational Analysis of the SRS Phase III Salt Disposition Alternatives

In this study, the state-of-the art for estimating LERF is considered for the regulatory risk-informed decisions. The consideration is mainly focused on (1) the relationship between Level 2 PSA and LERF evaluation methodology, (2) the standard requirements in terms of modeling preparation and the acceptance criteria based on the application capability II of ASME PRA standard, and (3) some pending issues for developing and proposing a simplified LERF model. This study is preliminarily presented and will be updated for establishing detailed evaluation scheme of extended MPAS (multi-purpose probabilistic analysis of safety) model and preparing the technical basis.

2006-01-15

314

An application of possibilistic programming to the fuzzy location?allocation problems

Completion of the Phase III evaluation and comparison of salt disposition alternatives was supported with enhanced computer models and analysis for each case on the ''short list'' of four options. SPEEDUP(TM) models and special purpose models describing mass and energy balances and flow rates were developed and used to predict performance and production characteristics for each of the options. Results from the computational analysis were a key part of the input used to select a primary and an alternate salt disposition alternative.

1999-10-07

315

British Library Electronic Table of Contents (United Kingdom)

This paper considers location?allocation problem in the real uncertain world and develops a possibilistic non-linear programming model to deal with this problem. Fuzzy decision making in fuzzy environment concept is used to determine possibility distribution of location and allocation variables. To solve this model, a novel approach based on genetic algorithm structure is developed. As the proposed model includes both deterministic (location) and uncertain (allocation) parameters, the developed solution algorithm uses a hybrid chromosome structure. Also, to cover continuous nature of the problem and prevent GA from early convergence, a new crossover operator is introduced. Finally, performance of the developed algorithm is evaluated by an example.

2011-01-01

316

Utilization of low rank coals in liquefaction

Reversible performance loss induced by sequential failed cold start of PEM fuel cells

The objective of the current MITRE study is to estimate the cost of the coal derived liquid products that result from processing low rank coals in the Wilsonville and HRI CTSL configurations. The resultant cost of liquids is then compared to liquids produced from bituminous coals. The methodology used to accomplish the above objective was to utilize the MITRE coal liquefaction cost model to assess the overall technical and economic performance of low rank coals in both the Wilsonville and HRI configurations. Actual test data from Wilsonville and HRI was used as the basis for these analyses. This test data is modified to simulate complete resid recycle extinction and to standardize the operating performance of the deashing unit. This corrected yield data is then used in the simulation models to predict the overall performance and economics of a conceptual commercial coal liquefaction ...

1991-01-01

317

British Library Electronic Table of Contents (United Kingdom)

This study correlates the post start cell performance and impedance with the cold start process in the subzero environment. The sequential failed cold starts are deliberately conducted as well as the start at small current density. Here the failed cold start means the cell voltage drops to or below zero within very short time during the start process. It is found that there are reversible performance losses for the sequential failed cold starts, while not obvious degradation and no recovery happen for the start at small current density. Using the thin film and agglomerate model, it is confirmed that this is due to the water blocking effect. Comparing the results from different start processes, a model with respect to the shifting of reactive region within the catalyst layer is applied to e...

2011-01-01

318

A Study on Feature Selection Techniques in Educational Data Mining

Numerical solutions of high-frequency perturbations in Bianchi type IX models

Educational data mining (EDM) is a new growing research area and the essence of data mining concepts are used in the educational field for the purpose of extracting useful information on the behaviors of students in the learning process. In this EDM, feature selection is to be made for the generation of subset of candidate variables. As the feature selection influences the predictive accuracy of any performance model, it is essential to study elaborately the effectiveness of student performance model in connection with feature selection techniques. In this connection, the present study is devoted not only to investigate the most relevant subset features with minimum cardinality for achieving high predictive performance by adopting various filtered feature selection techniques in data mining but also to evaluate the goodness of subsets with different cardinalities and the quality of ...

2009-01-01

319

The effect of meal size on gastric evacuation in whiting

The problem in perturbation theory in general relativity is finding a natural gauge which simplifies the equations considerably. We solved the first and second order perturbation equations in the ''Lorentz gauge'' using the two-timing method. The equations were deduced from the equations of Einstein in the presence of a matter energy-momentum tensor of a perfect fluid with equation of state p = (..gamma..-1) rho. It is found that the 0--0 component of the first order equations together with the gauge conditions are consistent with the Bianchi type V model, without axial symmetry. It represents a ''ground state'' situation of the Bianchi type IX model (Mixmaster model.) The second order equations, describing the reaction back of the gravitational waves on the slowly varying background, give rise to rotation and will disturb the ...

1983-05-15

320

Predicting neuronal responses during natural vision.

Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe gastric evacuation was evaluated and compared with a power model expanded as a function of meal size. The model parameters were estimated by means of nonlinear least squares. When all meal sizes were included the estimates of the power (curvature) parameter in the expanded model were within the range 0.36-0.77 for the different prey. The power estimates in the simple model were generally close to 0.5. The exception was crustacean prey, which gave a higher value. In the simple model the power estimate represents a compromise between the curvatures of the ...

1998-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

321

Improved double-multiple streamtube model for the Darrieus-type vertical-axis wind turbine

A model that fully describes the response properties of visual neurons must be able to predict their activity during natural vision. While many models have been proposed for the visual system, few have ever been tested against this criterion. To address this issue, we have developed a general framework for fitting and validating nonlinear models of visual neurons using natural visual stimuli. Our approach derives from linear spatiotemporal receptive field (STRF) analysis, which has frequently been used to study the visual system. However, prior to the linear filtering stage typical of STRFs, a linearizing transformation is applied to the stimulus to account for nonlinear response properties. We used this approach to compare two models for neurons in primary visual cortex: a nonlinear Fourier power model, which accounts for spatial phase invariant tuning, and a traditional linear ...

322

GENERAL REQUIREMENTS FOR SIMULATION MODELS IN WASTE MANAGEMENT

Double streamtube codes model the curved blade (Darrieus-type) vertical-axis wind turbine (VAWT) as a double actuator-disk arrangement (one disk for the upwind half of the rotor and a second disk for the downwind half) and use conservation of momentum principles to determine the forces acting on the turbine blades and the turbine performance. These models differentiate between the upwind and downwind sections of the rotor and are capable of determining blade loading more accurately than the widely-used single-actuator-disk streamtube models. Additional accuracy may be obtained by representing the turbine as a collection of several streamtubes, each of which is modeled as a double actuator disk. This is referred to as the double-multiple-streamtube model. Sandia National Laboratories has developed a double-multiple streamtube model for the ...

1983-01-01

323

Thermal-fluid flow analysis and demonstration test of a spent fuel storage system

Most waste management activities are decided upon and carried out in a public or semi-public arena, typically involving the waste management organization, one or more regulators, and often other stakeholders and members of the public. In these environments, simulation modeling can be a powerful tool in reaching a consensus on the best path forward, but only if the models that are developed are understood and accepted by all of the parties involved. These requirements for understanding and acceptance of the models constrain the appropriate software and model development procedures that are employed. This paper discusses requirements for both simulation software and for the models that are developed using the software. Requirements for the software include transparency, accessibility, flexibility, extensibility, quality assurance, ability to do discrete and/or continuous simulation, ...

2003-02-27

324

The unsteady pressure field and the aerodynamic performances of a Savonius rotor based on the discrete vortex method

Thermal-fluid flow analysis and demonstration test were performed for a spent fuel storage system. The commercial computational fluid dynamics (CFD) code, FLUENT was used for the numerical analysis. Effective thermal conductivities of a spent fuel assembly and a fuel basket were derived to optimize a thermal analysis model. Also, a porous model, which can simplify a complex configuration of a fuel assembly, was used in the thermal analysis. Demonstration test were performed to verify the thermal analysis method and procedure using a half scaled-down model and an electrically heated dummy fuel. The numerical analysis results were compared with the experimental data. Thermal analyses of the storage system were carried out for normal and off-normal conditions by using the verified analysis method.

2009-03-15

325

Shared-memory performance of multiple computer terminals in parallel distributed information-processing systems

The aim of this paper is to numerically explore the non-linear two-dimensional unsteady potential flow over a Savonius rotor and to develop a code for predicting its aerodynamics performances. In the model developed, the rotor is represented in a median plane by two semicircles, displaced along their common diameter. The two semicircles can be considered to produce lifting effects. As a result, they are modelled by a collection of discrete vortices on their contours. The flow field is then governed by the Laplace equation. The versatile Neumann boundary condition, applied over the contour of the semicircles and the Kutta Joukowsky condition applied at the four extremities of the semicircles have been used in the modelling. The torque distribution of the stationary rotor and the unsteady pressure field on the blades of the rotating rotor, predicted by the code developed, have been compared and validated ...

2010-01-15

326

Role of the diffuse layer in acidic and alkaline fuel cells

A system model for transmission of computer user's data with a finite number of regular users in a resource-sharing mode in parallel distributed information-processing systems is considered. The mini/microcomputer included in the system model is considered to be receiving the mixed arrival data of the user from a picture-phone terminal with uniformly-distributed data arrivals and a teletypewriter terminal with Erlang-distributed data arrivals. The large-memory performance of the mini/microcomputer is analysed with the mixed input data, constant service-times, synchronous transmission and single server interruption through a first-order Markov process. A simple and general approach to calculate the data arrivals from picture-phone and teletypewriter terminals and their mixed data arrivals is presented. Expressions for memory content probability and average queueing delay are derived. The application of the ...

1984-03-01

327

British Library Electronic Table of Contents (United Kingdom)

A numerical model is developed to study electrolyte dependent kinetics in fuel cells. The model is based on the Poisson-Nernst-Planck (PNP) and generalized-Frumkin-Butler-Volmer (gFBV) equations, and is used to understand how the diffuse layer and ionic transport play a role in the performance difference between acidic and alkaline systems. The laminar flow fuel cell (LFFC) is used as the model fuel cell architecture to allow for the appropriate comparison of equivalent acidic and alkaline systems. We study the overall cell performance and individual electrode polarizations of acidic and alkaline fuel cells for both balanced and unbalanced electrode kinetics as well as in the presence of transport limitations. The results predict cell behavior based on electrolyte composition that strongly...

2011-01-01

328

MODELING AN ION EXCHANGE PROCESS FOR CESIUM REMOVAL FROM ALKALINE RADIOACTIVE WASTE SOLUTIONS

Energy accounting for shared virtualized environments under DVFS using PMC-based power models

The performance of spherical Resorcinol-Formaldehyde ion-exchange resin for the removal of cesium from alkaline radioactive waste solutions has been investigated through computer modeling. Cesium adsorption isotherms were obtained by fitting experimental data using a thermodynamic framework. Results show that ion-exchange is an efficient method for cesium removal from highly alkaline radioactive waste solutions. On average, two 1300 liter columns operating in series are able to treat 690,000 liters of waste with an initial cesium concentration of 0.09 mM in 11 days achieving a decontamination factor of over 50,000. The study also tested the sensitivity of ion-exchange column performance to variations in flow rate, temperature and column dimensions. Modeling results can be used to optimize design of the ion exchange system.

2008-08-26

329

British Library Electronic Table of Contents (United Kingdom)

Virtualized infrastructure providers demand new methods to increase the accuracy of the accounting models used to charge their customers. Future data centers will be composed of many-core systems that will host a large number of virtual machines (VMs) each. While resource utilization accounting can be achieved with existing system tools, energy accounting is a complex task when per-VM granularity is the goal. In this paper, we propose a methodology that brings new opportunities to energy accounting by adding an unprecedented degree of accuracy on the per-VM measurements. We present a system - which leverages CPU and memory power models based in performance monitoring counters (PMCs) - to perform energy accounting in virtualized systems. The contribution of this paper is threefold. First, w...

2012-01-01

330

Dynamic response analysis of pipe-restraints system. Analysis of pipe whip tests performed under PWR-LOCA conditions using 4-inch test pipe

Computational modeling of dynamic-failure mechanisms in armor/anti-armor materials. Final report, 1 Oct 88-30 Sep 91

This paper presents the results of the dynamic response analysis of the pipe-restraints system by the general purpose finite element program ADINA. The analysis was carried out for the pipe whip tests performed under the PWR-LOCA conditions using 4-in. test pipe. In the analysis, the test pipe was modeled by an assemblage of the beam elements with the isotropic elastic-plastic material properties and the restraints were represented by the truss elements with the nonlinear elastic material properties including gap effect. The following results are obtained through the analysis. (1) Pipe can be modeled with the beam elements, when the overhang length is short and, therefore, the flattening of a cross-section of pipe is small. (2) The steady state restraint force can be predicted by modeling the restraints with the truss elements.

1983-09-01

331

Analytical studies of four-inch pipe whip tests under BWR LOCA conditions

The purpose of this project was to develop improved dynamic failure models for brittle materials (primarily ceramics). The approach to developing these failure models was to establish a database (ACERAM) in which fundamental material properties and processing information could be directly correlated with ballistic performance data. Under this contract, a comprehensive literature search was conducted, many contacts were established in the armor/anti-armor research and development community, and database development was undertaken. A more limited project was also undertaken to assess and compare the effects of material properties and penetration mechanisms on the ballistic performance of depleted uranium and tungsten alloy penetrators.

1991-02-01

332

Uncertainty and Sensitivity of Alternative Rn-222 Flux Density Models Used in Performance Assessment

The purpose of pipe rupture studies in JAERI is to perform model tests on pipe whip, restraint behavior, jet impingement and jet thrust force, and to establish a computational method for analyzing these phenomena. This report presents the analytical results of 4-inch pipe whip tests under BWR LOCA conditions. Dynamic response analyses were performed using the general-purpose finite element program ADINA. The test pipe was modelled by straight beam elements and the four restraints were modelled by a single truss element. The analytical results were compared with the experimental results. Impact time and maximum total restraint force showed good agreement with experimental results. On the other hand, pipe strain and pipe deflection could not be predicted so well. The reason for this is that the sliding of the restraint during the pipe whip movement cannot be considered in the ...

1985-01-01

333

AIDE: internal dosimetry software.

Performance assessments for the Area 5 Radioactive Waste Management Site on the Nevada Test Site have used three different mathematical models to estimate Rn-222 flux density. This study describes the performance, uncertainty, and sensitivity of the three models which include the U.S. Nuclear Regulatory Commission Regulatory Guide 3.64 analytical method and two numerical methods. The uncertainty of each model was determined by Monte Carlo simulation using Latin hypercube sampling. The global sensitivity was investigated using Morris one-at-time screening method, sample-based correlation and regression methods, the variance-based extended Fourier amplitude sensitivity test, and Sobol's sensitivity indices. The models were found to produce similar estimates of the mean and median flux density, but to have different uncertainties and sensitivities. When ...

2007-06-01

334

Towards an objective evaluation of tolerances for beam modeling in a treatment planning system

AIDE (Activity and Internal Dose Estimates) is a software for calculating activities in compartments and committed doses due to occupational exposures, and for performing intake and dose estimates using bioassay data. It has been continuously developed and tested for more than 20 years. Its calculation core has been applied in several situations, like performing all dose estimates due to (137)Cs intakes, which occurred during the Goiania accident in 1987; performing quality assurance of the ICRP Task Group on Dose Calculations regarding calculations of activities in compartments and generation of dose coefficients for adults due to intakes by inhalation, ingestion and injection of several radionuclides; and producing the tables of activities in compartments and dose coefficients using the NCRP Wound Model for the NCRP report. It provides several capabilities like performing ...

2008-03-12

335

Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Solenoidal Magnetic Field I: Weak Magnetic Field Limit

The performance of a convolution/superposition based treatment planning system depends on the ability of the dose calculation algorithm to accurately account for physical interactions taking place in the tissue, key components of the linac head and on the accuracy of the photon beam model. Generally the user has little or no control over the performance of the dose calculation algorithm but is responsible for the accuracy of the beam model within the constraints imposed by the system. This study explores the dosimetric impact of limitations in photon beam modeling accuracy on complex 3D clinical treatment plans. A total of 70 photon beam models was created in the Pinnacle(TM) treatment planning system. Two of the models served as references for 6 MV and 15 MV beams, while the rest were created by perturbing the reference ...

2007-09-21

336

Neutron Resonance Parameters of 55Mn from Reich-Moore Analysis of Recent Experimental Neutron Transmission and Capture Cross Sections

Propagation of an intense charged particle beam pulse through a background plasma is a common problem in astrophysics and plasma applications. The plasma can effectively neutralize the charge and current of the beam pulse, and thus provides a convenient medium for beam transport. The application of a small solenoidal magnetic field can drastically change the self-magnetic and self- electric fields of the beam pulse, thus allowing effective control of the beam transport through the background plasma. An analytic model is developed to describe the self-magnetic field of a finite- length ion beam pulse propagating in a cold background plasma in a solenoidal magnetic field. The analytic studies show that the solenoidal magnetic field starts to infuence the self-electric and self-magnetic fields when ?ce > ?pe?b, where ?ce = e?/mec is the electron gyrofrequency, ?pe is the electron plasma frequency, and ...

2008-10-10

337

Synchronous orbit performance of Hughes Aircraft Company solar arrays - update

High-resolution neutron capture cross section measurements of 55Mn were recently performed at GELINA by Schillebeeckx et al. (2005) and at ORELA by Guber et al. (2007). The analysis of the experimental data was performed with the computer code SAMMY using the Bayesian approach in the resonance parameters representation of the cross sections. The neutron transmission data taken in 1988 by Harvey et al. (2007) and not analyzed before were added to the SAMMY experimental data base. More than 95% of the s-wave resonances and more than 85% of the p-wave resonances were identified in the energy range up to 125 keV, leading to the neutron strength functions S0 = (3.90 0.78) x 10-4 and S1 = (0.45 0.08) x 10-4. About 25% of the d-wave resonances were identified with a possible strength function of S2 = 1.0 x 10-4. The capture cross section calculated at 0.0253 eV is 13.27 b, and the capture resonance integral is 13.52 0.30 b. In the energy range 15 to ...

2008-05-01

338

Prospects for polarized target materials with pure carbon background.

The synchronous orbit performance of Hughes Aircraft Company solar arrays is presented and compared with the results of ground based predictions for orbital durations of almost 11 years. Performances of the Intelsat IV*, IVA*, and Telesat (Anik) solar arrays are detailed. This paper is an update of the in-orbit performances previously reported in 1976 (1). The in-space performance data indicate solar array power degradation of 16.7 percent for Intelsat IV F-2 after 130 months in orbit, and 13.0 percent for Telesat F-1 after 85 months in orbit. The predicted output of each of these solar arrays is within 2 percent of the actual in-orbit performance of these systems. The Intelsat IV F-2 experienced the 4 August 1972 solar flare. The ability to accurately predict the performance of solar arrays within telemetry accuracy is demonstrated. This ability combines the ...

1982-08-01

339

Fast Flux Test Facility (FFTF) Background & Status

No abstract available.

1992-01-01

340

Indicators of safety culture - selection and utilization of leading safety performance indicators

No abstract prepared.

2001-06-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

341

Reporting bias when using real data sets to analyze classification performance

Safety indicators play a role in providing information on organizational performance, motivating people to work on safety and increasing organizational potential for safety. The aim of this report is to provide an overview on leading safety indicators in the domain of nuclear safety. The report explains the distinction between lead and lag indicators and proposes a framework of three types of safety performance indicators - feedback, monitor and drive indicators. Finally the report provides guidance for nuclear energy organizations for selecting and interpreting safety indicators. It proposes the use of safety culture as a leading safety performance indicator and offers an example list of potential indicators in all three categories. The report concludes that monitor and drive indicators are so called lead indicators. Drive indicators are chosen priority areas of organizational safety activity. They are based on the ...

2010-05-01

342

British Library Electronic Table of Contents (United Kingdom)

Motivation: It is commonplace for authors to propose a new classification rule, either the operator construction part or feature selection, and demonstrate its performance on real data sets, which often come from high-dimensional studies, such as from gene-expression microarrays, with small samples. Owing to the variability in feature selection and error estimation, individual reported performances are highly imprecise. Hence, if only the best test results are reported, then these will be biased relative to the overall performance of the proposed procedure. Results: This article characterizes reporting bias with several statistics and computes these statistics in a large simulation study using both modeled and real data. The results appear as curves giving the different reporting biases as...

2010-01-01

343

Inspection pig for gas pipeline

Body size and predatory performance in wolves: is bigger better?

The ultrasonic inspection pig system was described as being under development. This system was said to adopt the unique wheel type ultrasonic sensor which does not need couplant. This pig was designed to detect external corrosion in long-distance pipelines without interruption of the gas service. The wall-thickness measurement performance test and the travel performance test of the inspection pig in the test line confirmed that these performances satisfied the development specifications. However, the effect induced by the inner surface properties of the pipe and the influence of the pipe`s performance over long distances and for a long period of time still needed to be verified in an actual gas pipeline, and while the pipeline was actually in service. Improvements to the prototype model of the inspection pig were expected to include combinations of inspection pigs, with increases in ...

1992-12-31

344

British Library Electronic Table of Contents (United Kingdom)

Summary Large body size hinders locomotor performance in ways that may lead to trade-offs in predator foraging ability that limit the net predatory benefit of larger size. For example, size-related improvements in handling prey may come at the expense of pursuing prey and thus negate any enhancement in overall predatory performance due to increasing size. This hypothesis was tested with longitudinal data from repeated observations of 94 individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park, USA. Wolf size was estimated from an individually based sex-specific growth model derived from body mass measurements of 304 wolves. Larger size granted individual wolves a net predatory advantage despite substantial variation in its effect on the performance ...

2009-01-01

345

Muon trigger, flavour tagging and physics performance of the LHCb experiment; Trigger a muons, etiquetage de la saveur et performances physiques de l'experience LHCb

Distortion-invariant color pattern recognition using multiple phase-shifted-reference-based joint transform correlation incorporating synthetic discriminant function

The LHCb experiment that is being settled in CERN is dedicated to the study of CP violation and rare decays in the field of beauty hadrons. The phenomenological background necessary to an adequate understanding of the physics of flavor is presented in the first chapter, it is shown how the flavordynamics can open the way to new physics. The second chapter is dedicated to a brief presentation of the LHCb detector. Two aspects of the design of the muon trigger are more detailed: the radiation resistance of the opto-electronic transmitters and the simulated performances of the trigger. The third chapter reviews the tasks linked to the tagging of the savors of B mesons which will be an important step in all the experiments made at LHCb. The recent progress in heavy savor physics as well as the expected contribution of LHCb in this field are presented in the fourth chapter, especially the search for new physics in penguin diagrams b {yields} s.

2007-10-15

346

Monte Carlo methods, models, and applications to the advanced neutron source

This paper proposes a new pattern recognition system employing optical joint transform correlation (JTC) technique which offers a great number of advantages over similar digital techniques, including very fast operation, simple architecture and capability of updating the reference image in real time. The proposed JTC technique incorporates a synthetic discriminant function (SDF) of the target image estimated from different training images to make the pattern recognition performance invariant to noise and distortion. It then involves four different phase-shifted versions of the same target SDF reference image, which are individually joint transform correlated with the given input scene. When the correlation signals are combined, it produces a single cross-correlation peak corresponding to each potential target present in the given input scene. The proposed technique also includes a fringe-adjusted filter to generate a delta-like correlation peak with high ...

2011-04-01

347

Hydrological evaluation of landfill performance (HELP) model assessment of the geology at Los Alamos National Laboratory, Technical Area 54, Material Disposal Area J

This paper reports on three-dimensional continuous-energy coupled neutron-gamma Monte Carlo models of the Advanced Neutron Source (ANS) final preconceptual and conceptual reference core designs developed using the Monte Carlo Neutron and Photon transport code (MCNP) Version 3b. These models contain the reactor core with control rods, the heavy water reflector tank with shutdown rods and some beam tubes, and the outer light water pool. Eighty homogenized fuel zones per fuel element are used to represent the radial and axial {sup 235}U fuel distribution. These models are the most sophisticated, physically accurate reactor physics models of the ANS currently available. The use of MCNP methods and applications to the ANS are demonstrated. Beam tube studies, coolant voiding studies, and many criticality studies have already been performed, as have studies with variance reduction ...

1991-09-01

348

Final report for the 'Melt-Vessel Interactions' Project. European Union R and TD Program 4th Framework. MVI project final research report

The purpose of this paper is: (1) conduct HELP model variations in weather data, profile characteristics, and hydraulic conductivities for major rock units; (2) compare and contrast the results of simulations; (3) obtain an estimation of leakage through the landfill from the surface to the aquifer; and (4) evaluate contaminant transport to the aquifer utilizing leakage estimation. The conclusions of this paper are: (1) the HELP model is useful to assess landfill design alternatives or the performance of a pre-existing landfill; (2) model results using site-specific data incorporated into the Weather Generator (Trail 4), varied significantly from generalized runs (Trials 1-3), consequently, models that lack site-specific data should be used cautiously; and (3) data from this study suggest that there will not be significant downward percolation of leachate from the surface of the ...

2002-01-01

349

Ageing assessments with application of PSA Models

The Melt Vessel Interaction (MVI) project is concerned with the consequences of the interactions that a core melt, generated during a postulated severe accident in a light water reactor, may have with the pressure vessel. In particular, the issues concerned with the failure of the vessel bottom head are the focus of the research. The specific objectives of the project are to obtain data and develop validated models, which could be applied to prototypic plants, and accident conditions, for resolution of issues related to the melt vessel interactions. The project work has been performed by nine partners having varied responsibility. The work included a large number of experiments, with simulant materials, whose observations and results are employed, respectively, to understand the physical mechanisms and to develop validated models. Applications to the prototypic geometry and conditions have also been ...

1995-10-01

350

Nonlinear stability analysis of a reduced order model of nuclear reactors: A parametric study relevant to the advanced heavy water reactor

One of the main applications of PSA studies is related to identification of the major key issues related to plant safety. In standard PSA one assumes a constant value for component failure rates by considering that the component doesn't experience any degradation that could affect its performance. Used in this manner, standard PSA tools do not adequately address important ageing issues, and this fact could have a significant impact on the conclusions drawn from PSA studies and applications, in conditions of operation of ageing plants. To obtain realistic results, it is necessary to consider in the PSA model the ageing effects, and to do that it is necessary to take into consideration the change in component failure rate as a function of component age. In case of ageing phenomena, this dependence causes the failure rate of a component (or a set of components) to increase in time as the component age increase. The paper presents the benefits of ...

2009-10-12

351

Preliminary study of the {alpha} ratio measurement, ratio of the neutron capture cross section to the fission one for {sup 233}U, on the PEREN platform. Development and study of the experimental setup; Etude preliminaire de la mesure du rapport {alpha}, rapport de la section efficace moyenne de capture sur celle de fission de l'{sup 233}U, sur la plateforme PEREN. Developpement et etude du dispositif experimental

Research highlights: ? We model power oscillations in boiling water reactors using a lumped parameter model. ? The nature and amplitudes of oscillations is obtained using a nonlinear analysis. ? The method of multiple scales has been used for the analytical treatment. ? Fuel temperature coefficient of reactivity determines the nature of oscillations. ? The presented systematic method of analysis useful for reduced order reactor models. - Abstract: In this paper, we perform a parametric study of the nonlinear dynamics of a reduced order model for boiling water reactors (BWR) near the Hopf bifurcation point using the method of multiple scales (MMS). Analysis has been performed for general values of the parameters, but the results are demonstrated for parameter values of the model corresponding to the advanced heavy water reactor (AHWR). The ...

2011-01-01

352

Optimization of Valve Disc Using Orthogonal Array and Kriging Model

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 ...

2007-12-15

353

Numerical Models of Sgr A*

A butterfly valve is a type of flow control device, typically used to regulate a fluid flowing. Currently, FEA is often used to predict the safety in the design of valve disc. Also, the study about the affection of butterfly valve's disc to the valve flow characteristics by using CFD has been done by many researchers. Along with the development of computer technique, design and analysis of computer experiments has becoming more and more important in engineering design and optimization. Hereinto Kriging model is one popular analysis approach for the purpose of creating a cheap ``meta-model'' as a surrogate to a computationally expensive simulation model. In this paper, the numerical analysis considered the strength, pressure loss coefficient and weight of valve disc simultaneously is investigated to improve the shape of a traditional butterfly valve disc. Firstly, an initial model of butterfly valve is ...

2008-10-01

354

3-D CFD MODEL OF A MULTI-CELL HIGH TEMPERATURE ELECTROLYSIS STACK

We review results from general relativistic axisymmetric magnetohydrodynamic simulations of accretion in Sgr A*. We use general relativistic radiative transfer methods and to produce a broad band (from millimeter to gamma-rays) spectrum. Using a ray tracing scheme we also model images of Sgr A* and compare the size of image to the VLBI observations at 230 GHz. We perform a parameter survey and study radiative properties of the flow models for various black hole spins, ion to electron temperature ratios, and inclinations. We scale our models to reconstruct the flux and the spectral slope around 230 GHz. The combination of Monte Carlo spectral energy distribution calculations and 230 GHz image modeling constrains the parameter space of the numerical models. Our models suggest rather high black hole spin ($a_*\\approx 0.9$), electron ...

2010-01-01

355

W, Z and H bosons in the three particle final states production at TeV energy #gamma#e and #gamma##gamma#colliders

A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis stack performance and steam electrolysis in the Idaho National Laboratory (INL) Integrated Lab Scale (ILS) experiment. The model is made of 60 planar cells stacked on top of each other operated as Solid Oxide Electrolysis Cells (SOEC). Details of the model geometry are specific to a stack that was fabricated by Ceramatec, Inc. and tested at INL. Inlet and outlet plenum flow and distribution are considered. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user defined subroutine was ...

2009-05-01

356

Underground Test Area Subproject Phase I Data Analysis Task. Volume V - Transport Parameter and Source Term Data Documentation Package

The short review of complete tree level calculations for three particle final states production at the future e"+e"-, #gamma#e and #gamma##gamma# colliders is presented. The results obtained with the help of CompHEP system for total cross sections and other characteristics of processes in the energy range 0.1-2 TeV are summarized and their comparison with the results of different approaches is discussed. In particular we are interested in the processes of W, Z and H boson production. The reactions under consideration are especially interesting in connection with probing of new couplings, searching for new particle signals and as an important backgrounds to these experiments. The main subjects described are basic reactions rates (sections 2,3), Higgs production in #gamma#e collisions (section 4), the possibilities of testing some four vector bosons interaction vertices and Higgs-fermion coupling (section 5), the process of excited neutrino production with the ...

1993-12-01

357

Underground Test Area Subproject Phase I Data Analysis Task. Volume III - Groundwater Recharge and Discharge Data Documentation Package

Volume V of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the transport parameter and source term data. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

1996-12-01

358

Three-dimensional modeling of the flow and the interface surface in a continuous casting mold model

Volume III of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the data covering groundwater recharge and discharge. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

1996-10-01

359

The contribution of lower vertebrate animal models in human reproduction research

A new methodology for three-dimensional (3-D) numerical modeling of the continuous steel casting process is presented and evaluated. The results are compared with available experimental data obtained in a water-oil mold model for various flow rates and immersion depths of the submerged entry nozzle. The water-oil interface pattern at the top of the mold is also investigated. Wave formation and evolution in time is simulated with a volume tracking method. The predicted flow field inside the mold exhibits quite satisfactory agreement with the corresponding measurements, whereas some quantitative differences are observed referring to the final wave amplitude at low casting speeds. Conclusions of scientific and engineering importance concerning both the computer algorithm and the mold performance are also drawn.

1999-12-01

360

British Library Electronic Table of Contents (United Kingdom)

Many advances have been carried out on the estrogens, GnRH and endocannabinoid system that have impact in the reproductive field. Indeed, estrogens, the generally accepted female hormones, have performed an unsuspected role in male sexual functions thanks to studies on non-mammalian vertebrates. Similarly, these animal models have provided important contributions to the identification of several GnRH ligand and receptor variants and their possible involvement in sexual behavior and gonadal function regulation. Moreover, the use of non-mammalian animal models has contributed to a better comprehension about the endocannabinoid system action in several mammalian reproductive events. We wish to highlight here how non-mammalian vertebrate animal model research contributes to advancements with i...

2011-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

361

Reliability-based robustness analysis for a Croatian sports hall

British Library Electronic Table of Contents (United Kingdom)

This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness and a simplified mechanical system modelling of a timber truss system. A complex timber structure with a large number of failure modes is modelled with only a few dominant failure modes. First, a component based robustness analysis is performed based on the reliability indices of the remaining elements after the removal of selected critical elements. The robustness is expressed and evaluated by a robustness index. Next, the robustness is assessed using system reliability indices where the probabilistic failure model is modelled by a series system of parallel systems.

2011-01-01

362

Proximity effect correction of a laser lithography process for photomask fabrication

Proximity effect correction of a laser lithography process for photomask fabrication

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-07-01

363

Predicting the subspecific identity of invasive species using distribution models: Acacia saligna as an example

We report on the improvement of Critical Dimension (CD) linearity on a photomask by applying the concept of process proximity correction to a laser lithographic process used for fabrication of photomasks. Rule-based Laser Process proximity Correction (LPC) was performed using an automated optical proximity correction tool and we obtained dramatic improvement of CD linearity on a photomask. A study on model-based LPC was executed using a two-Gaussian kernel function and we extracted model parameters for the laser lithographic process by fitting the model-predicted CD linearity data with measured ones. Model-predicted bias values of isolated space (I/S), Arrayed Contact (A/C) and Isolated Contact (I/C) were in good agreement with those obtained by the nonlinear curve-fitting method used for the rule-based LPC.

2004-11-04

364

British Library Electronic Table of Contents (United Kingdom)

Abstract Aim- To explore whether the subspecific genetic entities of Acacia saligna occupy different bioclimatic niches in their native and introduced ranges and whether these niches are predictable using species distribution models (SDMs). Location- Australia, South Africa and the Mediterranean Basin. Methods- Species distribution models were developed in MAXENT using six climatic variables to calculate the climatic suitability of the ranges of A.saligna. We assessed (1) the subspecific niche differences identified by SDMs using measures of niche overlap and model performance; (2) the ability of SDMs to predict the most likely subspecific genetic entities present in South Africa based on comparisons to genetic data; and (3) the ability of SDMs to predict the most likely subspecific geneti...

2011-01-01

365

Outcomes and Cost Analysis of Pyeloplasty for Antenatally Diagnosed Ureteropelvic Junction Obstruction Using Markov Models

British Library Electronic Table of Contents (United Kingdom)

Objectives The optimal timing of pyeloplasty for children diagnosed with ureteropelvic junction obstruction (UPJO) after workup for antenatal hydronephrosis is disputed. We sought to examine the potential costs and clinical outcomes of treatment protocols featuring different indications for pediatric pyeloplasty using Markov models. Methods Cost and outcomes analysis using Markov modeling was performed for three treatment algorithms: medical management, immediate pyeloplasty (during the first year of life), and pyeloplasty after no improvement on imaging. The costs were determined from the perspective of the medical institution. The variables tracked during Markov model simulation included age at resolution of UPJO, the proportion of patients with worsened hydronephrosis, the number of pye...

2008-01-01

366

Noninvasive prediction of vertebral body compressive strength using nonlinear finite element method and an image based technique

British Library Electronic Table of Contents (United Kingdom)

Noninvasive prediction of vertebral body strength under compressive loading condition is a valuable tool for the assessment of clinical fractures. This paper presents an effective specimen-specific approach for noninvasive prediction of human vertebral strength using a nonlinear finite element (FE) model and an image based parameter based on the quantitative computed tomography (QCT). Nine thoracolumbar vertebrae excised from three cadavers with an average age of 42 years old were used as the samples. The samples were scanned using the QCT. Then, a segmentation technique was performed on each QCT sectional image. The segmented images were then converted into three-dimensional FE models for linear and nonlinear analyses. A new material model was implemented in our nonlinear model being more...

2010-01-01

367

Long term corrosion on T91 and AISI1 316L steel in flowing lead alloy and corrosion protection barrier development: Experiments and models

British Library Electronic Table of Contents (United Kingdom)

Considering the status of knowledge on corrosion and corrosion protection and especially the need for long term compatibility data of structural materials in HLM a set of experiments to generate reliable long term data was defined and performed. The long term corrosion behaviour of the two structural materials foreseen in ADS, 316L and T91, was investigated in the design relevant temperature field, i.e. from 300 to 550degreeC. The operational window of the two steels in this temperature range was identified and all oxidation data were used to develop and validate the models of oxide scale growth in PbBi. A mechanistic model capable to predict the oxidation rate applying some experimentally fitted parameters has been developed. This model assumes parabolic oxidation and might be used for de...

2011-01-01

368

Interfacial area transport: data and models

Improved double-multiple streamtube model for the Darrieus-type vertical axis wind turbine

The objective of this research is to replace the current flow regime dependent interfacial area correlations in the thermal-hydraulic system analysis codes with an interfacial area transport equation, which dynamically models two-phase flow regime transitions. The interfacial area transport equation applicable to bubbly flows has been developed based on mechanistic modeling of bubble interaction. Detailed experiments have been performed for bubbly conditions in 2.54, 5.08 and 10.16-cm ID pipes to benchmark the model. This new approach predicts the continuous changes of the interfacial area and will eliminate artificial bifurcations stemming from the use of the static flow regime transition criteria. This paper presents the preliminary results of incorporating the one-group transport equation into the USNRC consolidated code, currently under development. The framework for the two-group transport equation ...

2001-05-23

369

Discretization of complex 3-D flow domains with adaptive hybrid grids

Double streamtube codes model the curved blade (Darrieus-type) vertical axis wind turbine (VAWT) as a double actuator fish arrangement (one half) and use conservation of momentum principles to determine the forces acting on the turbine blades and the turbine performance. Sandia National Laboratories developed a double multiple streamtube model for the VAWT which incorporates the effects of the incident wind boundary layer, nonuniform velocity between the upwind and downwind sections of the rotor, dynamic stall effects and local blade Reynolds number variations. The theory underlying this VAWT model is described, as well as the code capabilities. Code results are compared with experimental data from two VAWT's and with the results from another double multiple streamtube and a vortex filament code. The effects of neglecting dynamic stall and horizontal wind velocity distribution are also illustrated.

1983-01-01

370

Density measurements of coal samples by different probe gases and their interrelation

There is an ever increasing demand to perform flow simulations that incorporate the complete details of geometry as well as sophisticated flow physics. This has led to the development of numerical algorithms that can simulate the actual flow phenomena with greater fidelity. However, the success of these algorithms hinges on the grid that models the geometry. Grid generation methods for 2-D models have long existed and the general lack of complexity of the simpler 2-D models has not quite challenged the efforts in this area. However, demands for generating better 3-D geometric models for flow simulations involving complex geometries have completely changed the perspective of grid generation strategies. As a consequence, grid generation efforts have earned equal significance as that of numerical solver efforts.

1996-12-31

371

Comparative study of extraction methods for solar cell model parameters

Density is useful in deducing the spatial structure of coals. In this paper, nitrogen has been used instead of the commonly employed helium, for the gas displacement pycnometer based density determination of a number of coals of Indian origin. The results show that the nitrogen-based densities are always higher than the helium-based ones. Also, empirical relationships between the helium-based and nitrogen-based coal densities have been developed by two modeling methods, namely, multi-variable regression and artificial neural networks. Although the two models have fared well, the neural network model exhibits a relatively better prediction accuracy and generalization performance than the regression model. This study thus demonstrates that nitrogen, which is cheaper and easily available, can be used gainfully as the probe gas for estimating the true density of coals. 23 refs., 1 fig., ...

2007-07-15

372

Analysis on Correlation between AE Parameters and Stress Intensity Factor using Principal Component Regression and Artificial Neural Network

A comparative study of three methods for extracting solar cell parameters of the single-diode lumped-circuit model is presented, using experimental characteristics collected from two silicon cells over a range of illuminations and temperatures. The results show that the curve-fitting method can often give erroneous parameter values. The 5-point methods are found to be reliable and accurate in situations where the model is a good approximation of cell performance. The analytical 5-point method, however, has the added advantage of simplicity. It is also found that for the cell measured, the single diode model is valid at illuminations above one-half AM1 but gives non-physical parameter values at lower illumination.

1986-03-01

373

Analysis of the operating conditions influence on PEM fuel cell performances by means of a novel semi-empirical model

The aim of this study is to develop the methodology which enables to identify the mechanical properties of element such as stress intensity factor by using the AE parameters. Considering the multivariate and nonlinear properties of AE parameters such as ringdown count, rise time, energy, event duration and peak amplitude from fatigue cracks of machine element the principal component regression(PCR) and artificial neural network(ANN) models for the estimation of stress intensity factor were developed and validated. The AE parameters were found to be very significant to estimate the stress intensity factor. Since the statistical values including correlation coefficients, standard mr of calibration, standard error of prediction and bias were stable, the PCR and ANN models for stress intensity factor were very robust. The performance of ANN model for unknown data of stress intensity factor was better than ...

2001-02-15

374

British Library Electronic Table of Contents (United Kingdom)

The present paper concerns the development of a polymer electrolyte membrane (PEM) fuel cells model in order to analyse the behaviour of the cell varying its operating parameters such as temperature (70-120 ^oC), pressure (1-3 atm), relative humidity (35-100%) and CO content (0-200 ppm) in the feeding gas. The voltage output and the relative current of a generic PEM fuel cell has been predicted through a mathematical method based on semi-empirical correlations derived from the experimental data available in literature. The model has been implemented in a commercial process simulator (AspenPlus) and it has been validated by comparing the obtained results with further experimental data (not utilized for the model development). The comparison has underlined a good agreement with the experimen...

2011-01-01

375

An improved noise-robust voice activity detector based on hidden semi-Markov models

British Library Electronic Table of Contents (United Kingdom)

To improve the performance of voice activity detector (VAD) in noisy environments, this paper concentrates on three critical aspects related to noise robustness including speech features, feature distributions and temporal dependence. Based on the statistic on TIMIT and NOIZEUS, Mel-frequency cepstrum coefficients (MFCCs) are selected as speech features, Gaussian Mixture distributions (GMD) are applied to associate the observations in MFCC domain with both speech and non-speech states, and Weibull and Gamma distributions are used to explicitly model noise and speech durations, respectively. To integrate these aspects into VAD, the hidden semi-Markov model (HSMM) as a generalized hidden Markov model (HMM) is introduced first. Then the VAD decision is made according to the likelihood ratio t...

2011-01-01

376

SR 97 - Alternative models project. Discrete fracture network modelling for performance assessment of Aberg

Experimental parameters differentially affect the humoral response of the cholera-toxin-based murine model of food allergy

As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modeling approaches for geosphere performance assessment for a single hypothetical site. The hypothetical site, arbitrarily named Aberg is based on parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The Aberg model domain, boundary conditions and canister locations are defined as a common reference case to facilitate comparisons between approaches. This report presents the results of a discrete fracture pathways analysis of the Aberg site, within the context of the SR 97 performance assessment exercise. The Aberg discrete fracture network (DFN) site model is based on consensus Aberg parameters related to the Aespoe HRL ...

1999-08-01

377

User`s guide and documentation manual for microbial transport simulator

Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle immunomodulating factors or factors effective during response initiation, this maximal response-based model is less suitable due to a lack of sensitivity. Therefore, in attempts to identify essential parameters to fine-tune the immune response towards a submaximal level, potentially more sensitive, we were interested in characterizing the individual effects of the parameters in the CT-based model: CT dose, antigen type and dose, and number of immunizations. Methods: BALB/c mice were orally sensitized weekly for 3 or 7 weeks with graded doses of CT and various food antigens (soy-trypsin inhibitor, ovalbumin or ovomucoid). ...

2003-01-01

378

Expert system for the real-time management of alarms in an electric grid. Un systeme expert pour la gestion en temps reel des alarmes dans un reseau electrique

The microbial transport simulator (MTS) is a three-dimensional, three-phase, multiple-component numerical model that permits the study of the transport of microorganisms and nutrients in porous media. Microbial parameters incorporated into MTS include: Microbial growth and decay, microbial deposition, chemotaxis, diffusion, convective dispersion, tumbling, and nutrient consumption. Governing equations for microbial and nutrient transport are coupled with continuity and flow equations under conditions appropriate for a black oil reservoir. The model`s mathematical formulations and preparation procedures of data files for conducting simulations using MTS are described. A general background of microbial transport simulation is given in Section I and the governing equations, mechanisms, and numerical solutions of MTS are given in Section II. Explanations for preparing an input data file with reservoir and microbial transport ...

1993-10-01

379

Analysis of non-Gaussian CMB maps based on the N-pdf. Application to WMAP data

A model-base expert system is presented for the processing of alarm messages in power networks' control centers. This alarm processor, called GESTAL, generates concise diagnoses identifying the causes(s) of network disturbances and describing the operation of the protection and alarm systems which operate to isolate faulty components. Essentially, the alarm processor is an agenda driven expert system which is composed of a model of the power network's alarm and protection systems as well as several sets of rules. Based on the nextwork model, graph structures are constructed which represent relationships between alarms as they are received. These graph structures are then analysed in order to diagnose the disturbances(s). The alarm processor has been developed using the ART 3.0 programming language in a Symbolics Lisp-machine environment. Background material on expert systems, electric ...

1987-01-01

380

Further development of the unified multiscale Eulerian model for a broad range of spatial and temporal scales within the new National Environmental Modeling System

We present a new method based on the N-point probability distribution (pdf) to study non-Gaussianity in cosmic microwave background (CMB) maps. Likelihood and Bayesian estimation are applied to a local non-linear perturbed model up to third order, characterized by a linear term which is described by a Gaussian N-pdf, and a second and third order terms which are proportional to the square and the cube of the linear one. We also explore a set of model selection techniques (the Akaike and the Bayesian Information Criteria, the minimum description length, the Bayesian Evidence and the Generalized Likelihood Ratio Test) and their application to decide whether a given data set is better described by the proposed local non-Gaussian model, rather than by the standard Gaussian temperature distribution. As an application, we consider the analysis of the WMAP 5-year data at a resolution of around 2 degrees. At ...

2008-01-01

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381

Computer vision algorithms in DNA ploidy image analysis

A unified Nonhydrostatic Multiscale Model on the Arakawa B grid (NMMB) designed for a broad range of spatial and temporal scales has been under development within the Earth System Modeling Framework (ESMF) at the National Centers for Environmental Prediction (NCEP) as a part of the new National Environmental Modeling System (NEMS). The model follows the general modeling philosophy of the NCEP's WRF NMM grid-point regional dynamical core. The model uses the regular latitude-longitude grid for the global domain, and a rotated latitude-longitude grid in regional applications. The nonhydrostatic component of the model dynamics is introduced through an add-on module that can be turned on or off depending on resolution. The "isotropic" quadratic conservative finite-volume horizontal differencing employed in the model conserves ...

2009-04-01

382

A stochastic regime switching model for the failure process of a repairable system

The high incidence and mortality rates of prostate cancer have stimulated research for prevention, early diagnosis and appropriate treatment. DNA ploidy status of tumour cells is an important parameter with diagnostic and prognostic significance. In the current study, DNA ploidy analysis was performed using image cytometry technique and digital image processing and analysis. Tissue samples from prostate patients were stained using the Feulgen method. Images were acquired using a digital imaging microscopy system consisting of an Olympus BX-50 microscope equipped with a color CCD camera. Segmentation of such images is not a trivial problem because of the uneven background, intensity variations within the nuclei and cell clustering. In this study specific algorithms were developed in Matlab based on the most prominent image segmentation approaches that emanate from the field of Mathematical Morphology, focusing on region-based watershed ...

2006-03-01

383

Simulations of Groundwater Flow and Radionuclide Transport in the Vadose and Saturated Zones beneath Area G, Los Alamos National Laboratory

This paper presents a stochastic model and estimation procedure for analyzing the failure process of a repairable system. We consider repairable systems whose successive interfailure times reveal a significant dependence while showing an insignificant trend. Neither the renewal process nor the non-homogeneous Poisson process are adequate for modeling such failure processes. Especially when the interfailure times show a cyclic pattern, we may consider a switching of the regimes (states) governing the lifetime distribution of the system. We propose a Markov switching model describing the failure process for such a case. The model postulates that a finite number of states governs the distinct lifetime distributions, and the state makes transitions according to a discrete-time Markov chain. Each of the distinct lifetime distributions represents a failure type that may change after successive repairs. Our ...

1998-02-01

384

Performance prediction of 20 kWp grid-connected photovoltaic plant at Trieste (Italy) using artificial neural network

Numerical simulations are used to predict the migration of radionuclides from the disposal units at Material Disposal Area G through the vadose zone and into the main aquifer in support of a radiological performance assessment and composite analysis for the site. The calculations are performed with the finite element code, FEHM. The transport of nuclides through the vadose zone is computed using a three-dimensional model that describes the complex mesa top geology of the site. The model incorporates the positions and inventories of thirty-four disposal pits and four shaft fields located at Area G as well as those of proposed future pits and shafts. Only three nuclides, C-14, Tc-99, and I-129, proved to be of concern for the groundwater pathway over a 10,000-year period. The spatial and temporal flux of these three nuclides from the vadose zone is applied as a source term for the three-dimensional ...

1999-07-01

385

Characteristics of the Receptor for the Biosphere Model

Growing of PV for electricity generation is one of the highest in the field of the renewable energies and this tendency is expected to continue in the next years. Due to the various seasonal, hourly and daily changes in climate, it is relatively difficult to find a suitable analytic model for predicting the performance of a grid-connected photovoltaic (GCPV) plant. In this paper, an artificial neural network is used for modelling and predicting the power produced by a 20 kWp GCPV plant installed on the roof top of the municipality of Trieste (latitude 45 deg. 40'N, longitude 13 deg. 46'E), Italy. An experimental database of climate (irradiance and air temperature) and electrical (power delivered to the grid) data from January 29th to May 25th 2009 has been used. Two ANN models have been developed and implemented on experimental climate and electrical data. The first one is a multivariate ...

2010-12-01

386

The effects of surface damage on RF cavity operation

This analysis report is one of a series of technical reports that document the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the geologic repository at Yucca Mountain. This report is one of the five biosphere reports that develop input parameter values for the biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes the conceptual model, as well as the mathematical model and its input parameters. Figure 1-1 is a graphical representation of the documentation hierarchy for the ERMYN. This figure shows relationships among the products (i.e., scientific analyses and model reports) developed for biosphere modeling and biosphere abstraction ...

2005-04-05

387

On the off-design of a natural gas-fired combined cycle with CO{sub 2} capture

We describe a model of damage in rf cavities and show how this damage can limit cavity operation. We first present a review of mechanisms that may or may not affect the ultimate fields that can be obtained in rf cavities, assuming that mechanical stress explains the triggers of rf breakdown events. We present a method of quantifying the surface damage caused by breakdown events in terms of the spectrum of field enhancement factors, Beta, for asperities on the surface. We then model an equilibrium that can develop between damage and conditioning effects, and show how this equilibrium can determine cavity performance and show experimental evidence for this mechanism. We define three functions that quantify damage, and explain how the parameters that determine this performance can be factored out and measured. We then show how this model can quantitatively explain the dependence of ...

2006-04-14

388

In-pile measurements of fuel rod deformation and verification of the finite element model FEMAXI

During the last 15 years cycles with CO{sub 2} capture have been in focus, due to the growing concern over our climate. Often, a natural gas fired combined cycle with a chemical absorption plant for CO{sub 2} capture from the flue gases have been used as a reference in comparisons between cycles. Neither the integration of the steam production for regeneration of amines in the combined cycle nor the off-design behaviour of such a plant has been extensively studied before. In this paper, the integration of steam production for regeneration of the amines is modelled at design load and studied in off-design conditions for a combined cycle. Different ambient conditions and part-load strategies and their influence on the cycle performance are also examined. Of particular interest is a novel strategy with the possibility of longer life of gas turbine blading, with marginal loss in efficiency. The off-design performance of the ...

2007-04-15

389

mtDNA mutation C1494T, haplogroup A, and hearing loss in Chinese

For safety evaluations and licensing procedures, fuel rod performance is predicted through model calculations. Due to the complexity of fuel rod performance and the insufficient availability of experimental data, such calculations necessarily reflect inaccuracies and conservatism. For verification and development of more realistic models and submodels, acquisition of reliable on-line data on fuel rod performance characteristics is imperative. The present paper describes the instruments and equipment applied in the Halden Reactor for on-line measurements of fuel rod and assembly power and power distribution, and fuel rod axial and diameter deformation. Recent results from evaluation of such fuel rod deformation measurements, covering fuel rods with different designs, subjected to various modes of operation, including startup ramps, steady state, and power shock, are presented. It is ...

1976-09-13

390

British Library Electronic Table of Contents (United Kingdom)

Mutation C1494T in mitochondrial 12S rRNA gene was recently reported in two large Chinese families with aminoglycoside-induced and nonsyndromic hearing loss (AINHL) and was claimed to be pathogenic. This mutation, however, was first reported in a sample from central China in our previous study that was aimed to reconstruct East Asian mtDNA phylogeny. All these three mtDNAs formed a subclade defined by mutation C1494T in mtDNA haplogroup A. It thus seems that mutation C1494T is a haplogroup A-associated mutation and this matrilineal background may contribute a high risk for the penetrance of mutation C1494T in Chinese with AINHL. To test this hypothesis, we first genotyped mutation C1494T in 553 unrelated individuals from three regional Chinese populations and performed an extensive search ...

2006-01-01

391

Transient azotaemia is associated with a high risk of death in hospitalized patients

British Library Electronic Table of Contents (United Kingdom)

Background.There are no suitably powered epidemiological studies of `transient azotaemia' (TA). The objective of this study was to describe the epidemiology of TA and its independent association with hospital mortality. We hypothesized that TA would be associated with an independent increase in the risk of death. Methods.We retrospectively studied all patients admitted to a university-affiliated hospital in Australia between January 2000 and December 2002. Patients were excluded if they were <15 years old, were on chronic dialysis, had kidney transplant or if their length of hospital stay was <24 hours. We defined TA as rapidly recovering acute kidney injury (AKI) (return to no-AKI risk, injury, failure, loss, end stage (RIFLE) class within 72 hours of onset). We performed descriptive and ...

2010-01-01

392

The Burden and Determinants of Neck Pain in the General Population

British Library Electronic Table of Contents (United Kingdom)

Study Design Best evidence synthesis. Objective To undertake a best evidence synthesis of the published evidence on the burden and determinants of neck pain and its associated disorders in the general population. Summary of Background Data The evidence on burden and determinants of neck has not previously been summarized. Methods The Bone and Joint Decade 2000?2010 Task Force on Neck Pain and Its Associated Disorders performed a systematic search and critical review of literature published between 1980 and 2006 to assemble the best evidence on neck pain. Studies meeting criteria for scientific validity were included in a best evidence synthesis. Results We identified 469 studies on burden and determinants of neck pain, and judged 249 to be scientifically admissible; 101 articles related to...

2008-01-01

393

Subaqueous deposition of reactive mine tailings in an open trench; Deposition subaquatique de residus miniers reactifs dans une fosse a ciel ouvert

Spectroscopic measurement of the Doppler broadening region of He II line emission of DT plasmas using impurity pellets

This poster presentation gave an overview of the subaqueous deposition of reactive mine tailings in the open trench Don Rouyn, located near Rouyn-Noranda, Quebec. The author began by providing a brief background of subaqueous mine tailing storage, and discussed the interest of the Don Rouyn trench. The site was described according to geomorphological and geological aspects. The hydrology conditions existing at the site were mentioned, and the results of the hydrology analysis performed were indicated. Close monitoring of the situation was maintained, and the chemical and physical stability of the tailings were evaluated. The conditions that prevailed both before and after the flooding of the site were explained. Water quality is being monitored, and the results obtained at this site might be used at other locations. 40 figs.

2000-07-01

394

Sleep and environmental context: interactive effects for memory

The feasibility of spectroscopic measurement of the velocity distribution of alpha particle using the ablation cloud of a lithium or boron pellet was tested in the DT experiment of TFTR. The measurement was performed using a 10-channel narrow-band filtered spectrometer in the wavelength covering the 3.5 MeV alpha particle Doppler broadening region of the He II 468.6 nm line and its vicinity. The spectra from a lithium pellet consists of the continuum bremsstrahlung background, lithium line emissions and possibly a 468.6 nm helium line. However, no clear evidence of alpha particles was observed, even when boron pellets were injected. (orig.) 4 refs.

1997-03-01

395

British Library Electronic Table of Contents (United Kingdom)

Sleep after learning is often beneficial for memory. Reinstating an environmental context that was present at learning during subsequent retrieval also leads to superior declarative memory performance. This study examined how post-learning sleep, relative to wakefulness, impacts upon context-dependent memory effects. Thirty-two participants encoded word lists in each of two rooms (contexts), which were different in terms of size, odour and background music. Immediately after learning and following a night of sleep or a day of wakefulness, memory for all previously studied words was tested using a category-cued recall task in room one or two alone. Accordingly, a comparison could be made between words retrieved in an environmental context which was the same as, or different to, that of the ...

2011-01-01

396

Single-Access Retroperitoneoscopic Adrenalectomy (SARA) Versus Conventional Retroperitoneoscopic Adrenalectomy (CORA): A Case?Control Study

British Library Electronic Table of Contents (United Kingdom)

Background Stimulated by the concept of Natural Orifice Transluminal Endoscopic Surgery (NOTES), minimizing the access even further has become a new trend in minimally invasive surgery. We compare our recently described new method of endoscopic single-access adrenalectomy with the conventional retroperitoneoscopic approach in a matched-pairs study. Methods Fifty single-access retroperitoneoscopic adrenalectomies (SARA) were performed in 47 selected patients suffering from Conn?s adenomas (n?=?20), pheochromocytomas (n?=?15), Cushing?s adenomas (n?=?6), and other diseases (n?=?6). For SARA, a single 2-cm skin incision beneath the 12th rib was used. Following creation of the retroperitoneal space with the rigid endoscope, dissection was carried out single-handed. Another 47 patients served a...

2010-01-01

397

Robotics in pediatric surgery: perspectives for imaging

Retroperitoneal endoscopic adrenalectomy is safe and effective

Robotic surgery will give surgeons the ability to perform essentially tremorless microsurgery in tiny spaces with delicate precision and may enable procedures never before possible on children, neonates, and fetuses. Collaboration with radiologists, engineers, and other scientists will permit refinement of image-guided technologies and allow the realization of truly remarkable concepts in minimally invasive surgery. While robotic surgery is now in clinical use in several surgical specialties (heart bypass, prostate removal, and various gastrointestinal procedures), the greatest promise of robotics lies in pediatric surgery. We will briefly review the history and background of robotic technology in surgery, discuss its present benefits and uses and those being explored, and speculate on the future, with attention to the current and potential involvement of imaging modalities and the role of image guidance. (orig.)

2004-06-01

398

British Library Electronic Table of Contents (United Kingdom)

AbstractBackground: The aim of this study was to review an experience with retroperitoneal endoscopic adrenalectomy (REA). This is the procedure of choice for adrenal tumours at this institution. Methods: Between 1997 and 2008, 112 REAs were performed in a single university centre. Data were retrieved retrospectively from a prospectively collected database, including information on patient demographics, surgical procedure, complications and hospital stay. Results: One hundred and twelve REAs were carried out successfully in 105 patients, including seven bilateral adrenalectomies. Thirty nine patients with unilateral adrenal disease had a phaeochromocytoma, of whom 16 had multiple endocrine neoplasia syndrome type 2, 21 patients had Cushing's disease and 20 had Conn's disease. Median body m...

2010-01-01

399

Plasma carotenoids and risk of acute myocardial infarction in the Singapore Chinese Health Study

British Library Electronic Table of Contents (United Kingdom)

Background and aimModification of low-density lipoprotein due to oxidative stress is essential in the development of coronary atherosclerosis. Data of specific carotenoids except b-carotene on cardioprotective effects in humans are limited. Methods and resultsThis study examined the associations between plasma concentrations of specific carotenoids and incidence of acute myocardial infarction. The study included 280 incident cases of acute myocardial infarction and 560 matched controls nested within the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese men and women aged 45-74 years old enrolled in 1993-1998 in Singapore. Retinol and carotenoids in prediagnostic plasma were quantified using high-performance liquid chromatography. High levels of plasma b-cryptoxanthin a...

2011-01-01

400

Neutron-induced fission cross-section of {sup 233}U in the energy range 0.5<E{sub n}< 20 MeV

Measurement properties of the pressure biofeedback unit in the evaluation of transversus abdominis muscle activity: a systematic review

The neutron-induced fission cross-section of {sup 233}U has been measured at the CERN n-TOF facility relative to the standard fission cross-section of {sup 235}U between 0.5 and 20MeV. The experiment was performed with a fast ionization chamber for the detection of the fission fragments and to discriminate against {alpha} -particles from the natural radioactivity of the samples. The high instantaneous flux and the low background of the n-TOF facility result in data with uncertainties of {approx} 3%, which were found in good agreement with previous experiments. The high quality of the present results allows to improve the evaluation of the {sup 233}U (n,f) cross-section and, consequently, the design of energy systems based on the Th/U cycle. (orig.)

2011-01-15

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401

British Library Electronic Table of Contents (United Kingdom)

Background: Measurements from pressure biofeedback units (PBUs) can be used to evaluate the activity of the transversus abdominis (TrA) muscle indirectly. These measurements can classify patients or monitor the progress of treatment programmes for people with low back pain. Objective: To systematically review studies on the measurement properties of PBUs for the assessment of TrA activity. Data sources: Eligible studies were identified through searches of PUBMED, CINAHL and BIREME (1990 to 2009). In addition, hand searches of journals and citation tracking were performed. Study selection: Full-text studies involving any type of clinimetric tests of PBU measurement for the assessment of TrA activity were selected. Data extraction: Two independent reviewers selected the studies, extracted th...

2011-01-01

402

Measurement of the total photoabsorption cross section on a proton in the energy range 600?1500 MeV at the GRAAL

British Library Electronic Table of Contents (United Kingdom)

The total photoabsorption cross section on a free proton was measured at the GRAAL facility in the energy range E ? = 600?1500 MeV. The large-aperture LAGRAN?E detector and a liquid hydrogen target were used in the experiment performed with a back-scattered Compton gamma beam. To improve the accuracy, two alternative methods were employed. First, a subtraction method of using empty-target measurements allowed the cross section ? tot to be evaluated directly because of a low level of the electromagnetic background. Second, an algorithm for evaluating ? tot on the basis of summing the dominating partial cross sections was developed. Experimental results obtained for ? tot by the two methods are compared with existing data.

2008-01-01

403

Lack of Association of the Genotype in the GNAS Fok I Polymorphism and Prostate Cancer

British Library Electronic Table of Contents (United Kingdom)

Abstract Background: G proteins are ubiquitously expressed signal transduction proteins playing a key role in multiple signal transduction pathways. The Gas subunit has been considered as an apoptosis factor. In this study the role of GNAS T393C genotypes of the GNAS gene encoding Gas was analyzed for its influence on the development and progression of prostate cancer. Methods: Genotyping of the GNAS T393C polymorphism in 196 prostate cancer patients and 200 healthy controls was performed by DNA extraction followed by PCR and restriction analysis. Results: We observed no evidence of effects related to GNAS T393C genotype as demonstrated by a comparison of the genotype distribution in prostate cancer patients and healthy controls, the genotype distribution dependent on grade of the primary ...

2011-01-01

404

Improving surgical outcome following the Norwood procedure

British Library Electronic Table of Contents (United Kingdom)

Background The Norwood procedure consists of three palliative operations, performed in neonates with hypoplastic left heart syndrome. Especially the first stage (Norwood I) is associated with the highest mortality rates in paediatric cardiac surgery (up to 25%). During surgery, the aorta is reconstructed and a systemic-to-pulmonary shunt is applied. Originally the modified Blalock-Taussig shunt was used, but recently the right-ventricle-to-pulmonary-artery shunt is increasingly being employed. We reviewed the results of our operative strategy, where an individualised choice of shunt is made. Furthermore, attempts to reduce interstage mortality (between Norwood I and II) were assessed. Methods All neonates who underwent Norwood stage I palliation from August 2004 until November 2010 were in...

2011-01-01

405

Improving functional esophageal surgery with a ?smart? bougie: endoflip

British Library Electronic Table of Contents (United Kingdom)

Background An emerging imaging tool, the functional lumen imaging probe (Endoflip; Crospon Ltd, Galway, Ireland), provides a real-time measurement of esophagogastric junction (EGJ) capacity and diameter, which would be of particular interest in functional esophageal surgery such as Heller myotomy and antireflux procedures. This study aimed to demonstrate the intraoperative use of endoflip in the treatment of achalasia and gastroesophageal reflux disease (GERD). Methods In the first case, Heller myotomy was performed under endopflip guidance, for persistent dysphagia after failed endoscopic dilatation. In the second case, the endoflip was used to calibrate a Nissen fundoplication. With the patient under general anesthesia, the endoflip catheter was inserted orally and positioned to straddle...

2011-01-01

406

Enhanced In Vivo Function of Bioartificial Lungs in Rats

British Library Electronic Table of Contents (United Kingdom)

BackgroundMore than 11 million Americans live with chronic lung disease; in search for an alternative to donor organs, we attempted to regenerate lungs based on perfusion decellularized lung scaffolds that can be transplanted similar to a donor organ. MethodsCadaveric rat lungs were decellularized by detergent perfusion. Resulting scaffolds were mounted in bioreactors and seeded with endothelial and fetal lung cells. Biomimetic organ culture was maintained for 7 days. Resulting bioartificial left lungs were transplanted in orthotopic position after left pneumonectomy in rats. Cadaveric left lung transplants and pneumonectomies served as controls. Blood gas analyses, compliance testing, and fluoroscopies were performed on postoperative days 1, 7, and 14. Lungs were removed for final analysi...

2011-01-01

407

Effect of Heart Rate on Ventricular Repolarization in Healthy Individuals Applying Vectorcardiographic T Vector and T Vector Loop Analysis

British Library Electronic Table of Contents (United Kingdom)

Background: Ventricular repolarization (VR) is strongly influenced by heart rate (HR) and autonomic nervous activity, both of which also are important for arrhythmogenesis. Their relative influence on VR is difficult to separate, but might be crucial for understanding while some but not other individuals are at risk for life-threatening arrhythmias at a certain HR. This study was therefore designed to assess the -pure- effect of HR increase by atrial pacing on the ventricular gradient (VG) and other vectorcardiographically (VCG) derived VR parameters during an otherwise unchanged condition. Methods: In 19 patients with structurally normal hearts, a protocol with stepwise increased atrial pacing was performed after successful arrhythmia ablation. Conduction intervals were measured on averag...

2011-01-01

408

Delaying the superficial inferior epigastric artery flap: A solution to the problem of the small calibre of the donor artery

British Library Electronic Table of Contents (United Kingdom)

Background: Superficial inferior epigastric artery (SIEA) flap has a great advantage over other flaps of the area, that is, readily non-existent donor-site problems. The main reason why the SIEA flap has never been extensively used in breast reconstruction is the small diameter and variable anatomy of its donor artery. This study presents a possibility of enlarging the SIEA diameter using the delay-phenomenon mechanism. Methods: A prospective clinical study of 26 patients was undertaken. Prior to surgery, ultrasound examinations were performed, measuring the diameter of SIEA and the velocity of blood flow in SIEA. The ipsilateral deep inferior epigastric artery (DIEA) was then ligated in all patients who had a measurable SIEA preoperatively. Two weeks later, measurements were repeated. The...

2011-01-01

409

Cost minimization analysis for combinations of sampling techniques in bronchoscopy of endobronchial lesions

British Library Electronic Table of Contents (United Kingdom)

SummaryBackground The choice of sampling techniques in bronchoscopy with sampling from a visible lesion will depend on the expected diagnostic yields and the costs of the sampling techniques. Aims The aim of this study was to determine the most economical combination of sampling techniques when approaching endobronchial visible lesions. Methods A cost minimization analysis was performed. All bronchoscopies from 2003 and 2004 at Haukeland university hospital, Bergen, Norway, were reviewed retrospectively for diagnostic yields. 162 patients with endobronchial disease were included. Potential sampling techniques used were biopsy, brushing, endobronchial needle aspiration (EBNA) and washings. Costs were estimated based on registration of equipment costs and personnel costs. Sensitivity analyse...

2009-01-01

410

Cosmic ray antiproton/electron discrimination capability of the CAPRICE silicon-tungsten calorimeter using neural networks

Binary pseudo-random grating as a standard test surface formeasurement of modulation transfer function of interferometricmicroscopes

A data analysis based on an artificial neural network classifier is proposed to identify cosmic ray antiprotons detected with the CAPRICE silicon-tungsten imaging calorimeter against electron background in the energy range 1.2-4.0 GeV. A set of new physical variables, describing the events inside the calorimeter on the base of their different patterns, are introduced in order to discriminate between hadronic and electromagnetic showers. The ability of the artificial neural network classifier to perform a careful multidimensional analysis gives the possibility to identify antiprotons with an electron rejection 408{+-}85 (stat) at 95.0{+-}0.2 (stat)% of signal detection efficiency. The high accuracy achieved by this method improves substantially the efficiency in the evaluation of the cosmic ray antiproton spectrum. (orig.).

1996-11-01

411

An economic comparison of female sterilization of hysteroscopic tubal occlusion with laparoscopic bilateral tubal ligation

The task of designing high performance X-ray optical systemsrequires the development of sophisticated X-ray scattering calculationsbased on rigorous information about the optics. One of the mostinsightful approaches to these calculations is based on the powerspectral density (PSD) distribution of the surface height. The majorproblem of measurement of a PSD distribution with an interferometricand/or atomic force microscope arises due to the unknown ModulationTransfer Function (MTF) of the instruments. The MTF characterizes theperturbation of the PSD distribution at higher spatial frequencies. Here,we describe a new method and dedicated test surfaces for calibration ofthe MTF of a microscope. The method is based on use of a speciallydesigned Binary Pseudo-random (BPR) grating. Comparison of atheoretically calculated PSD spectrum of a BPR grating with a spectrummeasured with the grating provides the desired calibration of theinstrumental MTF. The theoretical ...

2007-07-25

412

British Library Electronic Table of Contents (United Kingdom)

Background This study compares the expected 5-year costs for permanent sterilization in women between nonincisional hysteroscopic tubal occlusion with the Essure? system performed in an office setting and laparoscopic bilateral tubal ligation (LBTL). Study Design An economic decision tree is used to predict outcomes and costs to compare these two procedures from a US Medicaid perspective over a 5-year time horizon. Results Expected costs are $2367 for Essure? and $3545 for LBTL (Essure? saves $1178 or 33% of LBTL costs). Sensitivity analyses show Essure? has lower expected costs across all values considered. If the cost for a LBTL procedure were to decrease by 20% and the cost for Essure? to increase by 20%, Essure? would have still have lower expected costs. Conclusion Office-based steril...

2009-01-01

413

A phase II trial of sorafenib in first-line metastatic urothelial cancer: a study of the PMH Phase II Consortium

British Library Electronic Table of Contents (United Kingdom)

Summary Background Sorafenib is an oral multikinase inhibitor that blocks cell proliferation via the ERK pathway and angiogenesis via the VEGF pathway. This phase II trial was conducted to determine the efficacy and tolerability of sorafenib for the treatment of patients with metastatic urothelial cancer (UC) who had not had prior chemotherapy for advanced disease. Patients and Methods Seventeen chemo-na?ve UC patients with adequate performance status and organ function were treated with sorafenib 400?mg twice daily on a continuous basis until progression or unacceptable toxicity. The primary endpoint was objective tumor response rate as measured by RECIST criteria. Secondary endpoints included rate of prolonged stable disease (>3?months), time to progression, median and 1?yr survival and ...

2011-01-01

414

A comparative study of standard versus laparoendoscopic single-site surgery (LESS) totally extraperitoneal (TEP) inguinal hernia repair

British Library Electronic Table of Contents (United Kingdom)

Background Laparoscopic inguinal hernia repair has been around since the 1990s. A novel surgical approach known as laparoendoscopic single-site surgery (LESS) has been developed to reduce the port-related morbidities and improve the cosmetic outcomes of laparoscopic surgery, including totally extraperitoneal (TEP) inguinal hernia repair. The aim of the present study was to evaluate the safety and feasibility of the LESS TEP technique for inguinal hernia repair and compare the outcomes with the standard TEP approach. Methods Between January and May 2009, 54 consecutive healthy patients (48 men and 6 women) underwent LESS TEP inguinal hernia repair at our institute. All procedures were performed using our homemade single port for simultaneous passage of the laparoscope and instruments. The p...

2011-01-01

415

THE BURST MODE OF ACCRETION AND DISK FRAGMENTATION IN THE EARLY EMBEDDED STAGES OF STAR FORMATION

Plasma neutralization models for intense ion beam transport in plasma

We revisit our original papers on the burst mode of accretion by incorporating a detailed energy balance equation into a thin-disk model for the formation and evolution of circumstellar disks around low-mass protostars. Our model includes the effect of radiative cooling, viscous and shock heating, and heating due to stellar and background irradiation. Following the collapse from the prestellar phase allows us to model the early embedded phase of disk formation and evolution. During this time, the disk is susceptible to fragmentation, depending upon the properties of the initial prestellar core. Globally, we find that higher initial core angular momentum and mass content favors more fragmentation, but higher levels of background radiation can moderate the tendency to fragment. A higher rate of mass infall onto the disk than that onto the star is a necessary but not a sufficient ...

2010-08-20

416

Frequency analysis of daily rainfall in Han River basin based on regional L-moments algorithm

Plasma neutralization of an intense ion pulse is of interest for many applications, including plasma lenses, heavy ion fusion, cosmic ray propagation, etc. An analytical electron fluid model has been developed based on the assumption of long charge bunches (l{sub b} >> r{sub b}). Theoretical predictions are compared with the results of calculations utilizing a particle-in-cell (PIC) code. The cold electron fluid results agree well with the PIC simulations for ion beam propagation through a background plasma. The analytical predictions for the degree of ion beam charge and current neutralization also agree well with the results of the numerical simulations. The model predicts very good charge neutralization (>99%) during quasi-steady-state propagation, provided the beam pulse duration {tau}{sub b} is much longer than the electron plasma period 2{pi}/{omega}{sub p}, where {omega}{sub p} = (4{pi}e{sup ...

2003-05-01

417

Sources of competitive advantage and business performance in the European meat processing industry

At-site and regional frequency analyses of annual maximum 1-, 2-, and 3-days rainfall in Han River basin was performed and compared based on the regional L-moments algorithm. To perform regional frequency analysis, Han River basin was subdivided into 3 sub-basins such as South Han River, North Han River, and downstream regions. For each sub-basin, the discordancy and homogeneity tests were performed. As the results of goodness of fit tests, lognormal model was selected as an appropriate probability distribution for both South Han River and downstream regions and gamma-3 model for North Han River region. From Monte Carlo simulation, RBIAS and RRMSE of the estimated quantiles from regional frequency analysis and at-site frequency analysis were calculated and compared each other. Regional frequency analysis shows less RRMSE of the estimated quantiles than at-sites frequency analysis in ...

2001-04-30

418

Multiple concentric annuli for characterizing spatially nonuniform backgrounds

1. The aim of the paper is to investigate the relative importance of three sets of sources of competitive advantages on business performance in a specific industry context, ie the European meat processing industry. The three sets of competitive sources are Firm Specific Advantages (FSAs), Localizational Specific Advantages (LSAs) and Relationship Specific Advantages (RSAs). Based on a literature study, each set of competitive advantages is briefly described in terms of their theoretical antecedents. Seven hypotheses are formulated regarding the direct as well as the indirect relationships between the FSAs, LSAs and RSAs and business performance. Also, the direction of causality between the various sets of explanatory variables is considered. The hypotheses are combined in a structural modelling of firm competition. 2. Data and measurements are derived from a survey in the European meat processing industry in which 133 meat ...

1999-01-01

419

Why Gabor Frames? Two Fundamental Measures of Coherence and Their Role in Model Selection

A method is presented for estimating the background at a given location on a sky map by interpolating the estimated background from a set of concentric annuli which surround this location. If the background is nonuniform but smoothly varying, this method provides a more accurate (though less precise) estimate than can be obtained with a single annulus. Several applications of multi-annulus background estimation are discussed, including direct testing for point sources in the presence of a nonuniform background, the generation of "surrogate maps" for characterizing false alarm rates, and precise testing of the null hypothesis that the background is uniform.

1999-01-01

420

Unsaturated zone flow modeling for GWTT-95

The problem of model selection arises in a number of contexts, such as subset selection in linear regression, estimation of structures in graphical models, and signal denoising. This paper generalizes the notion of "incoherence" in the existing literature on model selection and introduces two fundamental measures of coherence---termed as the worst-case coherence and the average coherence---among the columns of a design matrix. It utilizes these two measures of coherence to provide an in-depth analysis of two variants of a simple one-step thresholding (OST) algorithm for model selection and proves that OST is feasible for model selection as long as the design matrix obeys an easily verifiable property. One of the key insights offered by the ensuing analysis in this regard is that if the design matrix has reasonably small worst-case and average coherence then OST ...

2010-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

421

Spiral Waves and Shocks in Discs around Black Holes: Low Compressibility and High Compressibility models

In accordance with the Nuclear Regulatory Commission regulation regarding groundwater travel times at geologic repositories, various models of unsaturated flow in fractured tuff have been developed and implemented to assess groundwater travel times at the potential repository at Yucca Mountain, Nevada. Kaplan used one-dimensional models to describe the uncertainty and sensitivity of travel times to various processes at Yucca Mountain. Robey and Arnold et al. used a two-dimensional equivalent continuum model (ECM) with inter- and intra-unit heterogeneity in an attempt to assess fast-flow paths through the unsaturated, fractured tuff at Yucca Mountain (GWTT-94). However, significant flow through the fractures in previous models was not simulated due to the characteristics of the ECM, which requires the matrix to be nearly saturated before flow through the fractures is initiated. In the current study ...

1995-12-31

422

Semiempirical model based on thermodynamic principles for determining 6 kW proton exchange membrane electrolyzer stack characteristics

Some authors have concluded that spiral structures and shocks do not develop if an adiabatic index gamma > 1.16 is adopted in accretion disc modelling, whilst others have claimed that they obtained well defined spirals and shocks adopting a gamma = 1.2 and a M_2/M_1 = 1 stellar mass ratio. In our opinion, it should be possible to develop spiral structures for low compressibility gas accretion discs if the primary component is a black hole. We considered a primary black hole of 8 solar mass and a small secondary component of 0.5 solar mass to favour spiral structures formations and possible spiral shocks via gas compression due to a strong gravitational attraction. We performed two 3D SPH simulations and two 2D SPH simulations and characterized a low compressibility model and a high compressibility model for each couple of simulations. 2D models reveal spiral structures existence. ...

2001-12-01

423

Integrated model of the shallow and deep hydrothermal systems in the East Mesa area, Imperial Valley, California

The performance of a 6 kW proton exchange membrane (PEM) electrolyzer was modeled using a semiempirical equation. Total cell voltage was represented as a sum of the Nernst voltage, activation overpotential and ohmic overpotential. A temperature and pressure dependent Nernst potential, derived from thermodynamic principles, was used to model the 20 cell PEM electrolyzer stack. The importance of including the temperature dependence of various model components is clearly demonstrated. The reversible potential without the pressure effect decreases with increasing temperature in a linear fashion. The exchange current densities at both the electrodes and the membrane conductivity were the coefficients of the semiempirical equation. An experimental system designed around a 6 kW PEM electrolyzer was used to obtain the current-voltage characteristics at different stack temperatures. A nonlinear curve fitting ...

2008-12-01

424

Final report of the European Passive Solar Modelling Sub-Group

Geological, geophysical, thermal, petrophysical and hydrological data available for the East Mesa hydrothermal system that are pertinent to the construction of a computer model of the natural flow of heat and fluid mass within the system are assembled and correlated. A conceptual model of the full system is developed and a subregion selected for quantitative modeling. By invoking the Boussinesq approximation, valid for describing the natural flow of heat and mass in a liquid hydrothermal system, it is found practical to carry computer simulations far enough in time to ensure that steady-state conditions are obtained. Initial calculations for an axisymmetric model approximating the system demonstrate that the vertical formation permeability of the deep East Mesa system must be very low (k/sub v/ approx. 0.25 to 0.5 md). Since subsurface temperature and surface heat flow data exhibit major deviations from ...

1982-01-01

425

A comparison of two operational wave assimilation methods

The task of selecting reliable computer programs to simulate the performance of passive solar buildings has been assigned by the CEC to a specialized sub-group, the Modelling Sub-Group. This group has selected a detailed program for large computers, which has been commissioned and run by each participant. It has also given a reference for the analysis of a set of simple models, i.e. for mini/micro computers, pocket calculators and manual methods. These simulation techniques have been analyzed by answering an original questionnaire, making test runs of the models with building and climatic data, and comparing the results obtained with the large program. The best manual method has been included in the Passive Solar Handbook prepared by the Passive Solar Working Group. The MSG has also established a comparative table of all the selected simplified models, in order to make the designer ...

1985-01-01

426

Radiological performance assessment for the E-Area Vaults Disposal Facility

A comparison is carried out between two operational wave forecasting/assimilation models for the North Sea, with the emphasis on the assimilation schemes. One model is the WAM model, in combination with an optimal interpolation method (OIP). The other model, DASWAM, consists of the third generation wave model PHIDIAS in combination with an approximate implementation of the adjoint method. In an experiment over the period February 19 - March 30, 1993, the models are driven by the same wind field (HIRLAM analysis winds), and the same observation data set is assimilated. This set consists of a) spectra from three pitch-and-roll buoys and b) Synthetic Aperture Radar (SAR) spectra from the ERS-1 satellite. Three analysis/forecast runs are performed: one without assimilation, one with assimilation of buoy measurements only, and one with all data ...

1997-01-01

427

Pre-waste-emplacement ground-water travel time sensitivity and uncertainty analyses for Yucca Mountain, Nevada; Yucca Mountain Site Characterization Project

This report is the first revision to ``Radiological Performance Assessment for the E-Area Vaults Disposal Facility, Revision 0'', which was issued in April 1994 and received conditional DOE approval in September 1994. The title of this report has been changed to conform to the current name of the facility. The revision incorporates improved groundwater modeling methodology, which includes a large data base of site specific geotechnical data, and special Analyses on disposal of cement-based wasteforms and naval wastes, issued after publication of Revision 0.

2000-04-11

428

New aspects for the evaluation of radioactive waste disposal methods

Yucca Mountain, Nevada is a potential site for a high-level radioactive-waste repository. Uncertainty and sensitivity analyses were performed to estimate critical factors in the performance of the site with respect to a criterion in terms of pre-waste-emplacement ground-water travel time. The degree of failure in the analytical model to meet the criterion is sensitive to the estimate of fracture porosity in the upper welded unit of the problem domain. Fracture porosity is derived from a number of more fundamental measurements including fracture frequency, fracture orientation, and the moisture-retention characteristic inferred for the fracture domain.

1993-01-01

429

Multilayer ultra high gradient insulator technology

For the performance assessment of radioactive and hazardous waste disposal sites, risk assessments are usually performed for the long term, i.e., over an interval in space and time for which one can predict movement and behavior of toxic agents in the environment. This approach is based on at least three implicit assumptions: One, that the engineering layout will take care of the immediate endangerment of potential receptors; two, that one has carefully evaluated just how far out in space and time the models can be extrapolated, and three, that one can evaluate potential health effects for very low exposures. A few of these aspects will be discussed here in the framework of the scientific method.

1996-08-18

430

Improvement of assessment methodology for fluid flow characteristics of passive flow control device

We are investigating a novel insulator concept which involves the use of alternating layers of conductors and insulators with periods less than 1 mm. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We present our ongoing studies investigating the degradation of the breakdown electric field resulting from surface roughness, the effect of gas pressure, and the performance of the insulator structure under bi-polar stress. Further, we present our initial modeling studies.

1998-03-27

431

Field validation of cable monitoring and rating system (CMARS) laboratory model. Semi-annual report, 1 May 1979-31 December 1979

The objective of this study is to establish evaluation and verification guideline for the APR 1400 and to investigate the thermal-hydraulic characteristics for fluidic device is analyzed using FLUENT. The scope and major results of research are flow characteristics for fluidic device. In this study, three-dimensional numerical model for fluidic device is developed adequately for, and results are compared with experimental data performed by VAPER (VAlve Performance Evaluation test Rig) in KAERI with an aim to verify numerical simulation. In addition, the parametric study has also carried out to investigate the effect of major parameters such as velocity and pressure inside FD chamber.

2002-10-01

432

Clean Technology Application : Kupola Model Burner for Increasing the Performance of Spent Accu Recycle

One year of research on validating the performance of the Cable Monitoring and Rating System (CMARS) is reported. The performance testing was conducted on underground 230-kV and 345-kV pipe type cable circuits owned by the New Jersey Public Service Electric and Gas Co. Laser temperature monitoring systems and a data acquisition system were installed. Software installation and development is discussed. The CMARS testing program is described. (LCL)

1980-01-01

433

An investigation of passive ventilation cooling and control strategies for an educational building

Recycling of used battery for recovering lead done by either small household/small scale industries has been identified as a source of air pollution, especially by heavy metal (Pb). This condition give an adverse impact toward workers and societies. Technological aspect is one of the causal. The process apply an open system. Therefore, a lot of energy, as well as dust wasted to the air without prior treatment. For overcoming this condition, closed system by utilizing Cupola furnace will be offered as one of the alternatives clean technology application and to increase the recovering performance in order to set an effective and efficient result. (author)

2000-02-01

434

Acceptance test of full scope simulator of Daya Bay NPP

Many non-domestic buildings, built recently in the UK, use natural means to provide ventilation for indoor air quality and thermal comfort. This paper presents monitoring results obtained from such a purpose built naturally ventilated educational building. Its performance during the summer is discussed based on monitored results. Using thermal and ventilation modelling, the paper also discusses the optimisation of the building's summer performance. Recommendations on the selection of appropriate ventilation strategies in relation to the prevailing external conditions are derived and the appropriateness of the control methods is discussed. (author)

2001-02-01

435

Effects of potential models on the adsorption of ethane and ethylene on graphitized thermal carbon black. Study of two-dimensional critical temperature and isosteric heat versus loading.

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.

436

Climate Impacts on US Energy Infrastructure: A New High Resolution Model, Policy Implications and Feedbacks

Adsorption of ethylene and ethane on graphitized thermal carbon black and in slit pores whose walls are composed of graphene layers is studied in detail to investigate the packing efficiency, the two-dimensional critical temperature, and the variation of the isosteric heat of adsorption with loading and temperature. Here we used a Monte Carlo simulation method with a grand canonical Monte Carlo ensemble. A number of two-center Lennard-Jones (LJ) potential models are investigated to study the impact of the choice of potential models in the description of adsorption behavior. We chose two 2C-LJ potential models in our investigation of the (i) UA-TraPPE-LJ model of Martin and Siepmann for ethane and Wick et al. for ethylene and (ii) AUA4-LJ model of Ungerer et al. for ethane and Bourasseau et al. for ethylene. These models are used to study the adsorption of ethane ...

2004-12-01

437

Time dependent unavailability analysis of nuclear safety systems considering periodically tested components

We describe the development of a fully coupled climate model configuration where the Community Climate System Model (CCSM) has been coupled with the VERDE (Visualizing Energy Resources Dynamically on the Earth) analysis modules that compute the response of the electric grid to temperature drivers. The VERDE model includes datasets characterizing the 26,500 sub-stations and 6,000 power generation stations fuel mix, efficiency, service areas, and future performance and these have been geo-located on a 1.4 degree latitude by 1.4 degree longitude CCSM grid (T85). The total electric customers have been computed using conversions derived from economic structure and population data. The carbon emissions per customer and the power generation in megawatts electric (MWe) have also been placed on reconciled 1 km, 4 km and the T85 climate model grid. The CCSM temperature for the present and ...

2010-12-01

438

Development of a probabilistic timing model for the ingestion of tap water.

It is of utmost importance to have a computer code in order to analyze how different parameters (like test duration time) affect the unavailability of safety systems of nuclear. In this context, a study was performed in order to evaluate the model employed by the FRANTIC computer code, which performs detailed calculations on the contribution to the system unavailability originated by hardware failures, component tests and repairs, aiming at considering the influence of different test schemes on the system unavailability. It was shown, by means of the results attained that the numerical model used by the FRANTIC code and the analytical model proposed by APOSTOLAKIS and CHU (4) give unavailability values much similar when the component tests are supposed to be perfect. When a test is supposed to be imperfect (that is, when it may induce a test is supposed to be imperfect (that is, ...

1974-06-05

439

Assessment of RELAP5/MOD3/CANDU"+ to Wolsung-1 D_2O leakage event

A contamination event in a water distribution system can result in adverse health impacts to individuals consuming contaminated water from the system. Assessing impacts to such consumers requires accounting for the timing of exposures of individuals to tap-water contaminants that have time-varying concentrations. Here we present a probabilistic model for the timing of ingestion of tap water that we developed for use in the U.S. Environmental Protection Agency's Threat Ensemble Vulnerability Assessment and Sensor Placement Tool, which is designed to perform consequence assessments for contamination events in water distribution systems. We also present a statistical analysis of the timing of ingestion activity using data collected by the American Time Use Survey. The results of the analysis provide the basis for our model, which accounts for individual variability in ingestion timing and provides a series of ...

2009-01-01

440

The Multipoles Factory An Element of the LHC Control

In order to evaluate the integrated performance of RELAP5/MOD3/CANDU"+ for CANDU operational transient analysis, we assesed the code to the D_2O leakage event occurred at Wolsung-I, 600 MW(e) CANDU reactor, on Oct. 20, '94. D_2O leakage event was initiated by stuck opening of liquid relief valve No.4 in primary coolant pressure and level control system. Assessment calculation was performed for the plant transients up to 1000 seconds after the initiating event. Calculation results are compared with those measured in primary heat transport system, pressure and inventory control system and boiler secondary system. Comparison with the plant trip log shows that the RELAP5/CANDU"+ is able to simulate the plant transients properly, from which we can conclude that the RELAP5/CANDU"+ is validated for application to CANDU operational transient analysis. CANDU specific models used in the assessment are fuel bundle heat transfer ...

2001-10-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

441

SOLID OXIDE FUEL CELL HYBRID SYSTEM FOR DISTRIBUTED POWER GENERATION

The measurements performed at CERN on prototypes and first pre-series main dipole magnets confirm the need of an active control of the Large Hadron Collider to compensate the dynamic field changes during the proton beam injection and acceleration. This control requires in turn an accurate forecast of the magnetic field in the accelerator. We plan to predict the field on the basis of two elements: theoretical field models tailored through the accumulated knowledge of the main magnets during series tests, and an on-line measurement system running on few reference magnets tracking the LHC current cycle. Data coming from this "Multipoles Factory" will result from the fusion of the two sources. Based on this system we foresee to deliver calibration information for pre-defined accelerator cycles as well as real time information for the active control. In this paper we report the conceptual design of the system, and we discuss the features and ...

2002-01-01

442

Ray-tracing simulation of the global propagation of inertia gravity waves through the zonally averaged middle atmosphere

This report summarizes the work performed by Honeywell during the October 2001 to December 2001 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a turbogenerator. The conceptual and demonstration system designs were proposed and analyzed, and these systems have been modeled in Aspen Plus. Work has also started on the assembly of dynamic component models and the development of the top-level controls requirements for the system. SOFC stacks have been fabricated and performance mapping initiated.

2003-08-01

443

Power correlation for vertical axis wind turbines with varying geometries

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.

1992-10-01

444

British Library Electronic Table of Contents (United Kingdom)

Abstract In this paper, a new predictive model that can forecast the performance of a vertical axis wind turbine (VAWT) is presented. The new model includes four primary variables (rotor velocity, wind velocity, air density, and turbine power output) as well as five geometrical variables (rotor radius, turbine height, turbine width, stator spacing, and stator angle). These variables are reduced to include the power coefficient (Cp) and tip speed ratio (TSR). A power coefficient correlation for a novel VAWT (called a Zephyr Vertical axis Wind Turbine (ZVWT)) is developed. The turbine is an adaptation of the Savonius design. The new correlation can predict the turbine's performance for altered stator geometry and varying operating conditions. Numerical simulations with a rotating reference f...

2011-01-01

445

Photodynamic efficacy of hypericin targeted by two delivery techniques to hepatocellular carcinoma cells

British Library Electronic Table of Contents (United Kingdom)

The photocytotoxic effect of hypericin (Hyp) targeted by two different delivery techniques, namely, liposomes and anti-hepatocyte specific antigen (anti-HSA) was investigated. Optical absorption and steady-state fluorescence were used to analyze the conjugation of Hyp with anti-HSA model and to evaluate the encapsulation capacity and drug release in a liposome model. Particle size and thermal analysis of the prepared liposomes were performed using laser-light scattering and differential scanning calorimetry (DSC), respectively. Viability study of HepG2 cells exposed to Hyp in the two delivery systems, in the dark and following visible light irradiation, was performed in comparison to free Hyp. The intracellular uptake and localization of Hyp in HepG2 cells were analyzed by means of spectro...

2010-01-01

446

PERFORMANCE-LIMITING DEFECTS IN CDZNTE DETECTORS.

Modelling and simulation of a solar cooler based on physical adsorption; Modelagem e simulacao de um refrigerador solar por adsorcao fisica

We studied the effects of small, <20 {micro}m, Te inclusions on the energy resolution of CdZnTe gamma-ray detectors using a highly collimated X-ray beam and gamma-rays, and modeled them via a simplified geometrical approach. Previous reports demonstrated that Te inclusions of about a few microns in diameter degraded the charge-transport properties and uniformity of CdZnTe detectors. The goal of this work was to understand the extent to which randomly distributed Te-rich inclusions affect the energy resolution of CZT detectors, and to define new steps to overcome their deleterious effects. We used a phenomenological model, which depends on several adjustable parameters, to reproduce the experimentally measured effects of inclusions on energy resolution. We also were able to hound the materials-related problem and predict the enhancement in performance expected by reducing the size and number of Te inclusions within ...

2006-10-29

447

Local binary pattern based features for sign language recognition

This study describes the construction of a simple mathematical model its validation through the simulation in transient state of a real cycle performed by a solar refrigerator based on physical adsorption using an activated carbon/methanol pair. The deviation from experimental results was 4% for the cycled mass of methanol, 2.2 % for maximum collector average temperature, and 3 x 10{sup -3} for the theoretical cycle coefficient of performance. Additional simulations of the same cycle inputting values representing different types and larger amounts of activated carbon showed the possibility of increasing the cycled methanol mass up to about 150%. (author) 26 refs., 16 figs., 9 tabs.

1993-12-31

448

British Library Electronic Table of Contents (United Kingdom)

In this paper we focus on appearance features describing the manual component of Sign Language particularly the Local Binary Patterns. We compare the performance of these features with geometric moments describing the trajectory and shape of hands. Since the non-manual component is also very important for sign recognition we localize facial landmarks via Active Shape Model combined with Landmark detector that increases the robustness of model fitting. We test the recognition performance of individual features and their combinations on a database consisting of 11 signers and 23 signs with several repetitions. Local Binary Patterns outperform the geometric moments. When the features are combined we achieve a recognition rate up to 99.75% for signer dependent tests and 57.54% for signer indep...

2011-01-01

449

Improvement of tracking performance using prediction-based algorithms for a maneuvering target

British Library Electronic Table of Contents (United Kingdom)

This paper presents a study involving prediction of a complicated maneuvering target, with the aim of improving the tracking performance of a fire control system (FCS). In this study, we predict the position of a complicated maneuvering target 5 s in advance using the information up to the current time. Because of the large error caused by the complicated maneuvers and the long prediction time interval, the mechanical system of the fire control system will take a heavy load. In order to cope with this problem, several approaches to decreasing the prediction error have been proposed including the prediction algorithms based on the multiple model(MM) filter, interacting multiple model (IMM) filter, and variable dimension with input estimation (VDIE) filter. Finally, comparative simulation re...

2011-01-01

450

Field tests on partial embedment effects (embedment effect tests on soil-structure interaction)

E-commerce usage and business performance in the Malaysian tourism sector: empirical analysis

A series of Model Tests of Embedment Effect on Reactor Buildings has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and lndustry (MITI) of Japan. The nuclear reactor buildings are partially embedded due to conditions for the construction or building arrangement in Japan. It is necessary to verify the partial embedment effects by experiments and analytical studies in order to incorporate the effects in the seismic design. Forced vibration tests, therefore, were performed using a model with several types of embedment. Correlated simulation analyses were also performed and the characteristics of partial embedment effects on soil-structure interaction were evaluated. (author)

1993-08-15

451

British Library Electronic Table of Contents (United Kingdom)

Purpose - Based upon the E-VALUE model developed, this paper aims to investigate the impact of e-commerce usage on business performance in the tourism sector. Design/methodology/approach - A cross-sectional survey is carried out on 165 Malaysian firms involved in the tourism sector (hotels, resorts, and hospitals engaged in health tourism) through the use of a structured questionnaire. Findings - The structural equation modeling results indicate that technology competency, firm size, firm scope, web-technology investment, pressure intensity, and back-end usage have significant influence on e-commerce usage. Among these variables, back-end integration is found to function as a mediator. E-commerce experience (in years) is found to moderate the relationship between e-commerce usage and busin...

2009-01-01

452

An analysis and evaluation of differential pressure calculation of motor operated valve using system flow model

A contribution to the study of the thermal behavior and of the electric performance of squirrel-cage induction motors; Uma contribuicao ao estudo do comportamento termico e do desempenho eletrico de motores de inducao com rotor em gaiola

As part of the EPRI Motor-Operated Valve (MOV) Performance Prediction Methodology, a System Flow Model (SFM) has been developed to determine the differential pressure (DP) across MOVs as they are stroked in typical power plant systems. Input to the SFM includes valve flow characteristics (such as flow coefficient) and system characteristics (such as pump head/flow curve). The primary output is differential pressure across the valve at each stroke position. The SFM was validated by comparison with test data from the EPRI Flow Loop Test Program. In this study, we calculated DP using SFM and performed DP test for four MOVs. Compared between calculated DP and test DP of four MOV, respectively good agreements are found. (author). 6 refs., 9 figs., 1 tab.

1999-11-01

453

Strings through the Microscope

A thermal-electric mathematical model for a squirrel cage induction motors which permits to specify the best motor for specific drive, under thermal and electric aspects based, only on manufacturer technical bulletins and technical information is presented. Changes of rotor parameters due Skin Effect and changes of winding resistances (both stator and rotor) with the temperature are considered. The accuracy of this model is appraised using experimental results. The thermal behavior and electric performance for some motors are obtained for continuos and intermittent duties with sinusoidal and non-sinusoidal voltages. (author)

1992-03-01

454

Stepping, Strain Gating, and an Unexpected Force-Velocity Curve for Multiple-Motor-Based Transport

Over the last few years, string theory has changed profoundly. Most importantly, novel duality relations have emerged which involve gauge theories of brane excitations on one side and various closed string backgrounds on the other. In this lecture, we introduce the fundamental ingredients of modern string theory and explain how they are modeled through 2D (boundary) conformal field theory. This so-called `microscopic description' of strings and branes is an active research area with new results ranging from the classification and construction of boundary conditions to studies of 2D renormalization group flows. We shall provide an overview of such developments before concluding the lecture with an extensive outlook on some research that is motivated by current problems in string theory. This includes investigations of non-rational and non-unitary conformal field theories.

2004-01-01

455

British Library Electronic Table of Contents (United Kingdom)

SummaryBackground Intracellular transport via processive kinesin, dynein, and myosin molecular motors plays an important role in maintaining cell structure and function. In many cases, cargoes move distances longer than expected for single motors; there is significant evidence that this increased travel is in part due to multiple motors working together to move the cargoes. Although we understand single motors experimentally and theoretically, our understanding of multiple motors working together is less developed. Results We theoretically investigate how multiple kinesin motors function. Our model includes stochastic fluctuations of each motor as it proceeds through its enzymatic cycle. Motors dynamically influence each other and function in the presence of thermal noise and viscosity. We...

2008-01-01

456

Resonances in gravitational scenario given by deformed branes

Practices for caring in nursing: Brazilian research groups

In this work we examine a five-dimensional brane-world model with brane structure driven by a real scalar field. From the deformation of a kink-like defect we find a new class of brane solutions containing internal structures which have implications for the way the background space-time is constructed and the way its curvature behaves. Initially, for spin 0 scalar field, we find a zero mode which can be localized on the deformed brane. However, this result can change by the gravitational interaction with the brane internal structure. Analyzing the massive modes of the scalar field, using two different methods, we find resonance structures similar to those found in the study of gravity localization. The main objective here is to observe the contributions of the deformation procedure to the resonances and to the well known field localization methods.

2011-08-01

457

British Library Electronic Table of Contents (United Kingdom)

ERDMANN A.L., DE ANDRADE S.R., FERREIRA DE MELLO A.L., KLOCK P., DO NASCIMENTO K.C., SANTOS KOERICH M. & STEIN BACKES D. (2011) Practices for caring in nursing: Brazilian research groups. International Nursing Review58, 379-385 Background:- The present study considers the production of knowledge and the interactions in the environment of research and their relationships in the system of caring in nursing and health. Aim:- To elaborate a theoretical model of the organization of the practices used for caring, based on the experiences made by the research groups of administration and management in nursing, in Brazil. Methods:- The study is based on grounded theory. Twelve leaders of research groups, working as professors in public universities in the south and the south-east of Brazil, distri...

2011-01-01

458

Nearly Conformal QCD and AdS/CFT

Myocardial pharmacokinetics of ebastine, a substrate for cytochrome P450 2J, in rat isolated heart

The AdS/CFT correspondence is a powerful tool to study the properties of conformal QCD at strong coupling in terms of a higher dimensional dual gravity theory. The power-law falloff of scattering amplitudes in the non-perturbative regime and calculable hadron spectra follow from holographic models dual to QCD with conformal behavior at short distances and confinement at large distances. String modes and fluctuations about the AdS background are identified with QCD degrees of freedom and orbital excitations at the AdS boundary limit. A description of form factors in space and time-like regions and the behavior of light-front wave functions can also be understood in terms of a dual gravity description in the interior of AdS.

2005-08-08

459

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND AND PURPOSE It is well established that cytochrome P450 2J (CYP2J) enzymes are expressed preferentially in the heart, and that ebastine is a substrate for CYP2J, but it is not known whether ebastine is metabolized in myocardium. Therefore, we investigated its pharmacokinetics in the rat isolated perfused heart. EXPERIMENTAL APPROACH Rat isolated hearts were perfused in the recirculating mode with ebastine for 130-min. The concentrations of ebastine and its metabolites, hydroxyebastine and carebastine, were measured using liquid chromatography with a tandem mass spectrometry. The data were analysed by a compartmental model. The time course of negative inotropic response was linked to ebastine concentration to determine the concentration-effect relationship. KEY RESULTS Ebastine w...

2011-01-01

460

Kriging analysis of soil properties

British Library Electronic Table of Contents (United Kingdom)

Background, aim, and scope Soil as a landscape body contains wide ranges of physical, chemical, morphological, and mineralogical properties, both laterally and vertically. Soils with similar properties and environments are expected to behave similarly. A statement on land use potential will depend in part on the precision and accuracy of the statements that can be made about the soils. This information has some practical applications in optimizing land management and productivity improvement. The spatial patterns and dependence of some selected physicochemical properties of brackish marsh and surrounding soils were investigated using a 2-D kriging analysis in conjunction with a geostatistical (GS+, Michigan) model. Materials and methods Composite (four subsamples) surface samples (0?20?cm)...

2008-01-01

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461

Interspecies Trait Genetics Reveals Association of Adcy8 with Mouse Avoidance Behavior and a Human Mood Disorder

British Library Electronic Table of Contents (United Kingdom)

Background Identifying susceptibility genes for endophenotypes by studying analogous behaviors across species is an important strategy for understanding the pathophysiology underlying psychiatric disorders. This approach provides novel biological pathways plus validated animal models critical for selective drug development. One such endophenotype is avoidance behavior. Methods In the present study, novel automated registration methods for longitudinal behavioral assessment in home cages are used to screen a panel of recently generated mouse chromosome substitution strains that are very powerful in quantitative trait loci (QTL) detection of complex traits. In this way, we identified chromosomes regulating avoidance behavior (increased sheltering preference) independent of motor activity lev...

2009-01-01

462

IEA Annex 27. Assessment of air quality, comfort and sound of ventilation systems in houses; IEA Annex 27. Beoordeling van woningventilatiesystemen op luchtkwaliteit, comfort en geluid

High energy photon-photon collisions

In the international study of IEA Annex 27 `Demonstration and evaluation of domestic ventilation systems` a number of simple tools to gain insight into the characteristics of ventilation systems for dwellings are presented. The assessment is made with respect to e.g. indoor air quality, comfort, noise, energy, costs and reliability. In three articles the results of Annex 27 will be discussed. In the first article background information of IEA Annex 27 was given as well as applications in the Netherlands. In this second article attention is paid to the assessment models (`simplified tools`) for indoor air quality, thermal comfort and noise. 6 refs.

1999-09-01

463

Epigenetic regulation of Myc on retinoic acid receptor beta and PDLIM4 in RWPE1 cells

The collisions of high energy photons produced at an electron-positron collider provide a comprehensive laboratory for testing QCD, electroweak interactions, and extensions of the standard model. The luminosity and energy of the colliding photons produced by backscattering laser beams is expected to be comparable to that of the primary e"+e"- collisions. In this overview, we shall focus on tests of electroweak theory in photon-photon annihilation, particularly #gamma##gamma##->#W"+W"-, #gamma##gamma##->#Higgs bosons, and higher-order loop processes, such as #gamma##gamma##->##gamma##gamma#, Z#gamma# and ZZ. Since each photon can be resolved into a W"+W"- pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. We also review high energy #gamma##gamma# tests of quantum chromodynamics, such as the scaling of the photon structure function, tt ...

464

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND Hypermethylation of CpG islands is a common epigenetic alteration associated with cancer. Tumor suppressor genes retinoic acid receptor beta (RARb) and PDLIM4 are hypermethylated and silenced in prostate cancer (PCa) tissues and PCa cell lines compared to normal prostate cells. METHODS In this study, a benign prostate epithelial cell line RWPE1 was used as a model to study the epigenetic regulation of Myc on the RARb and PDLIM4 promoters. Forced Myc overexpression inhibited the RARb and PDLIM4 expression. RESULTS Pyrosequencing study showed that Myc overexpression increased methylation in several CpG sites of both promoters. A DNA methylation inhibitor 5-aza-2prime-deoxycytidine reversed the epigenetic alteration effect of Myc on both RARb and PDLIM4. CONCLUSION The epigenetic r...

2009-01-01

465

Dendrosomes as novel gene porters-III

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND: It was previously reported that dendrosomes, i.e. neutral, biodegradable, covalent or self-assembled, hyperbranched, spheroidal nano-particles with a size ranging from 15 to 100 nm, provide a convenient and efficient means of gene delivery into various kinds of cells such as human hepatoma and kidney cells as well as animal models.RESULTS: New studies via circular dichroism show that hydrophilic and amphipathic dendrosomes either do not affect the DNA structure or moderately transform it from B- to A-conformation. Gene delivery into human liver, kidney, and endothelial cells as well as other animal cells like Bowes, U-937, Raw, CCRF-CEM, MOLT-4, K562, Huh-7 and VERO reveal that the genes are efficiently expressed and in comparison with other gene porters like Lipofectin or bact...

2008-01-01

466

Dark Matter and Electroweak Symmetry Breaking from $SO(10)$

Cosmological Information from Lensed CMB Power Spectra

We consider a minimal model of GUT scalar dark matter (DM) stabilized by the discrete gauge matter parity $P_{X}$ that arises from breaking of $SO(10)$. The dark sector comprises the complex singlet $S$ and the inert doublet $H_{2}$. GUT scale parameters are evaluated to the electroweak scale via Renormalization Group Equations (RGEs). Experimental and theoretical constraints limit the DM mass to the 80 GeV to 2 TeV range. The EW symmetry breaking is radiative and can occur via RGE running and 1-loop matching corrections from integrating out DM. Because the next-to-lightest scalar is almost degenerate with DM, it gives a background free displaced decay vertex at the LHC.

2010-01-01

467

Body mass index and risk of colorectal cancer in Chinese Singaporeans

Gravitational lensing distorts the cosmic microwave background (CMB) temperature and polarization fields and encodes valuable information on distances and growth rates at intermediate redshifts into the lensed power spectra. The non-Gaussian bandpower covariance induced by the lenses is negligible to l=2000 for all but the B polarization field where it increases the net variance by up to a factor of 10 and favors an observing strategy with 3 times more area than if it were Gaussian. To quantify the cosmological information, we introduce two lensing observables, characterizing nearly all of the information, which simplify the study of non-Gaussian impact, parameter degeneracies, dark energy models, and complementarity with other cosmological probes. Information on the intermediate redshift parameters rapidly becomes limited by constraints on the cold dark matter density and initial amplitude of fluctuations as observations improve. Extraction of ...

2006-01-01

468

British Library Electronic Table of Contents (United Kingdom)

AbstractBACKGROUND: The authors chose to examine the association between body mass index (BMI) and incident colorectal cancer across the spectrum of BMI, including underweight persons, because detailed prospective cohort data on this topic in Asians is scarce, as is data on underweight persons (BMI, <18.5 kg/m2) in any population. METHODS: Analysis of the Singapore Chinese Health Study included 51,251 men and women aged 45-74 years enrolled in 1993-1998 and followed through 2007. Incident cancer cases and deaths among cohort members were identified through record linkage, and 980 cases were identified. Cox regression models were used to investigate the association of baseline BMI with risk of incident colorectal cancer during a mean of 11.5 years of follow-up. RESULTS: A significant, U-sha...

2011-01-01

469

Assessment of cardio-respiratory interactions in preterm infants by bivariate autoregressive modeling and surrogate data analysis

British Library Electronic Table of Contents (United Kingdom)

Background: Cardio-respiratory interactions are weak at the earliest stages of human development, suggesting that assessment of their presence and integrity may be an important indicator of development in infants. Despite the valuable research devoted to infant development, there is still a need for specifically targeted standards and methods to assess cardiopulmonary functions in the early stages of life. We present a new methodological framework for the analysis of cardiovascular variables in preterm infants. Our approach is based on a set of mathematical tools that have been successful in quantifying important cardiovascular control mechanisms in adult humans, here specifically adapted to reflect the physiology of the developing cardiovascular system.Methods: We applied our methodology ...

2011-01-01

470

Applicability of the Chinese Version of the Prodromal Questionnaire

British Library Electronic Table of Contents (United Kingdom)

Background/Purpose Early detection and intervention of psychosis is clinically important. This study aimed to test the applicability of the Chinese version of the Prodromal Questionnaire (CPQ) for identifying prodromal states of psychosis. Methods This is a two-group cross-sectional comparative study. The Prodromal Questionnaire (PQ) was translated into traditional Chinese based on Brislins Revised Model. Like the PQ, the CPQ provides results on four subscales: (1) positive symptoms, (2) negative symptoms, (3) disorganized symptoms, and (4) general symptoms. An expert panel of five senior psychiatrists established the content validity of the CPQ. The experimental group was a sample of 100 first-visit patients to a psychiatric outpatient department (FVPOD). The comparison group comprised 98...

2010-01-01

471

APC and KRAS mutations in distal colorectal polyps are related to smoking habits in men: results of a cross-sectional study

British Library Electronic Table of Contents (United Kingdom)

Background The purpose of this study was (a) to evaluate the association between cigarette smoking and the prevalence of distal colorectal polyps and adenocarcinoma and (b) to analyse genetic alterations representing different molecular pathways of the colorectal carcinogenesis. Methods A total of 623 asymptomatic male (mean age: 53 years; 50?65) car factory workers were included. Information on smoking habits and other lifestyle factors were collected followed by a 60 cm colonoscopy. APC and KRAS mutations and microsatellite status were determined in colorectal lesions (colorectal carcinoma (CRC), hyperplastic (HP) and adenomatous polyps (AP)). Data were analysed using unconditional multiple logistic regression models. Results Smokers had a higher prevalence of AP (OR 2.1; 95% CI 1.2?3.6;...

2011-01-01

472

A risk calculator for glyphosate resistance in Lolium rigidum (Gaud.)

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND: Glyphosate resistance has been confirmed in 58 populations of Lolium rigidum (Gaud.), a major weed of crops in southern Australia. Extensive use of glyphosate in conjunction with minimal soil disturbance has been identified as high risk for resistance to that herbicide. Land managers need a simple method for rapid assessment of the risk of resistance occurring as a result of past and proposed future management practices. Modelled on risk assessment nomographs, a simple calculator for indicating the risk of evolved glyphosate resistance in L. rigidum is described.RESULTS: The calculator uses the generations since first use and the frequency of use of glyphosate in combination with historical cultivation levels as critical factors for determining the risk of glyphosate resistance...

2008-01-01

473

A report on the CCNA 2007 professional practice analysis.

Experimental investigation and modelling of tritium washout by precipitation in the area of the nuclear power plant of Paks, Hungary

The purpose of this column is to present the results of the 2007 Professional Practice Analysis (PPA) of the field of nurse anesthesia, conducted by the Council on Certification of Nurse Anesthetists. The PPA used survey and rating scale methodologies to collect data regarding the relative emphasis of various aspects of the nurse anesthesia knowledge domain and competencies. A total of 3,805 survey responses were analyzed using the Rasch rating scale model, which aggregates and transforms ordinal (rating scale) responses into linear measures of relative importance and frequency. Summaries of respondent demographics and educational and professional background are provided, as well as descriptions of how the survey results are used to develop test specifications. The results of this analysis provide evidence for the content outline and test specifications (content percentages) and thus serve as a basis of content validation for the National ...

2009-06-01

474

Use and disposal of large home electronic appliances in Vietnam

Tritium occurs in nature in trace amounts, but its concentration is changing due to natural and artificial sources. Studies focusing on natural tritium have to take into account the effect of artificial sources. Also, the impact of tritium is an important issue in environmental protection, e.g. in connection with the emissions from nuclear power plants. The present work focuses on the rain washout of tritium emitted from the Paks nuclear power plant in Hungary. Rainwater collectors were placed around the plant and after a period of precipitation, rainwater was collected and analysed for tritium content. Samples were analysed using low-level liquid scintillation counting, with some also subject to the more accurate "3He ingrowth method. The results clearly show the trace of the tritium plume emitted from the plant; however, values are only about one order of magnitude higher than environmental background levels. A washout model was devised to ...

2011-01-01

475

British Library Electronic Table of Contents (United Kingdom)

In this study, e-waste flows of five large home appliances (color televisions, refrigerators, washing machines, personal computers, and air conditioners) in Vietnam are investigated. A social survey was performed to investigate the situation on using appliances in households as well as on the disposal of appliances by the first users. Future quantities of e-waste were estimated using a model that combines use of the Weibull distribution, the logistic function, and the population balance model. It was forecast that about 3.86 million appliances, or 114 000 tons, will be discarded in 2010, and about 17.2 million appliances, or 567 000 tons, in 2025, showing a rapid increase of e-waste in the near future.

2009-01-01

476

The influence of the strength of hyperon-hyperon interactions on neutron star properties

Numerical simulation of trace tests in atmosphere in Daya Bay nuclear power site

An equation of state of neutron star matter with strange baryons has been obtained. The effects of the strength of hyperon-hyperon interactions on the equations of state constructed for the chosen parameter sets have been analysed. Numerous neutron star models show that the appearance of hyperons is connected with the increasing density in neutron star interiors. The performed calculations have indicated that a change of the hyperon-hyperon coupling constants affects the chemical composition of a neutron star. The obtained numerical hyperon star models exclude a large population of strange baryons in the star interior.

2005-09-01

477

Neural network for prediction of superheater fireside corrosion

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)

2005-09-01

478

Final report for Grant No. DOE/DE-FG02-98ER14909: Experimental and modeling studies of nanometer aerosol filtration

Superheater corrosion causes vast annual losses to the power companies. If the corrosion could be reliably predicted, new power plants could be designed accordingly, and knowledge of fuel selection and determination of process conditions could be utilized to minimize superheater corrosion. If relations between inputs and the output are poorly known, conventional models depending on corrosion theories will fail. A prediction model based on a neural network is capable of learning from errors and improving its performance as the amount of data increases. The neural network developed during this study predicts superheater corrosion with 80 % accuracy at early stage of the project. (orig.) 10 refs.

1998-12-31

479

Evaluation of the residual radiation field in the proton accelerator facility of the Proton Engineering Frontier Project (PEFP) in Korea

The primary objective is to perform a fundamental study of filtration of nanoparticles, and to obtain filtration knowledge necessary to design particle collection devices/systems for nanoparticle processing and for preventing nanoparticle emissions into the environment. The research covered a wide area relevant to nanoparticle filtration, under these main topics: (1) nanoparticle filtration and molecular dynamics simulation, (2) nanoparticle virtual impactor, (3) particle transport under low pressure, and (4) development of a high-throughput nanoparticle generator. A number of novel tools and numerical models have been developed under the DOE support.

2002-12-10

480

British Library Electronic Table of Contents (United Kingdom)

In Korea, the Proton Engineering Frontier Project (PEFP) is building a proton linear accelerator facility with energy up to 100MeV and a beam current of 20mA. In this study, a radiation field after shutdown in the accelerator facility of the PEFP was evaluated for the purpose of the radiation shielding by using MCNPX code. A facility modeling was performed for the accelerator tunnel building, accelerator chain, target rooms and beam experiment hall. And radiation source terms were evaluated in the facility. With this facility, model and radiation source terms, the concentration of 41Ar was evaluated and the cooling time satisfying regulation in Korea was calculated.

2007-01-01

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481

Computational Chemistry Study of Solvents for Carbon Dioxide Absorption

Collectivity at N=40 in neutron-rich "6"4Cr

Absorption with aqueous amine solvents is at present the most viable technology for CO{sub 2} capture. While this is a proven technology, efforts are ongoing to improve it in order to make it a more attractive technology for large scale use to reduce CO{sub 2} emissions. Finding solvents with better properties is one approach to improving the technology. In this thesis methods in computational chemistry are used to improve the understanding of the chemistry of CO{sub 2} absorption in amine-water systems. The work is also intended to provide models that can be used to predict the performance of new solvents. Such predictive models are intended to facilitate the screening for new solvents

2005-08-15

482

Analysis of the thermal performance of dynamic solar systems

"9Be-induced inelastic scattering of "6"2","6"4","6"6Fe and "6"0","6"2","6"4Cr was performed at intermediate beam energies. Excited states in "6"4Cr were measured for the first time. Energies and population patterns of excited states in these neutron-rich Fe and Cr nuclei are compared and interpreted in the framework of large-scale shell-model calculations in different model spaces. Evidence for increased collectivity and for distinct structural changes between the neighboring Fe and Cr isotopic chains near N=40 is presented.

2010-05-01

483

Advanced Fuel Cycle Economic Sensitivity Analysis

This article proposes a model for estimating the effect of the overall thermal resistance of the absorber and the coolant on a solar thermal energy system utilizing advanced heat transfer mediums. Two equations can be used to model a dynamic system: one for the maximum conversion efficiency and one to specify the constraint that, in quasi-steady state, the net energy collected must be transferred to the coolant. These two equations define a constrained optimization problem in two variables, the fluid and the absorber temperatures. The results present interesting implications for liquid metal, direct absorption, and solar evaporating systems.

1996-03-01

484

A mathematical model for a thermally coupled humidification?dehumidification desalination process

A fuel cycle economic analysis was performed on four fuel cycles to provide a baseline for initial cost comparison using the Gen IV Economic Modeling Work Group G4 ECON spreadsheet model, Decision Programming Language software, the 2006 Advanced Fuel Cycle Cost Basis report, industry cost data, international papers, the nuclear power related cost study from MIT, Harvard, and the University of Chicago. The analysis developed and compared the fuel cycle cost component of the total cost of energy for a wide range of fuel cycles including: once through, thermal with fast recycle, continuous fast recycle, and thermal recycle.

2006-12-01

485

British Library Electronic Table of Contents (United Kingdom)

The humidification?dehumidification process is an interesting technique that has been adapted for water desalination. Previous works experimentally investigated desalination processes in the shell and tube columns, where the humidification and dehumidification were thermally coupled and simultaneously performed at the tube and shell sides, respectively. In this work, a comprehensive steady-state mathematical model was developed for such a humidification?dehumidification desalination process by taking into account the heat and mass balances on both sides of the desalting column, the mass transfer rate at the humidification side, and the heat transfer rate between the dehumidification side and humidification side. Meanwhile, the mass transfer coefficient at the humidification side and the to...

2006-01-01

486

A comprehensive, numerical model of electro-thermal propulsion

Use of numerical wind-wave models for assessment of the offshore wave energy resource

A computer model of an electrothermal accelerator has been developed which applies to the plasma generator as well as the gun barrel, and it for the first time allows study of the interdependent physical processes in both components simultaneously. The code comprises a 2D transient description of the plasma arc, a 2D, two-phase interior ballistics module, and a preprocessor delivering the required plasma physical data. Some results on the flow field, pressure and temperature in a typical accelerator are presented, and probable limitations on the performance of such a system are discussed. The code is to be applied to different concepts of electrothermal chemical guns.

1993-01-01

487

A technique for determining the spatial and temporal distributions of surface fluxes of heat and moisture over the Southern Great Plains Cloud and Radiation Testbed

In the last two decades the performance of numerical wind-wave models has improved considerably. Several models have been routinely producing good quality wave estimates globally since the mid-1980s. The verifications of wind-wave models have mainly focused on the evaluation of the error of the significant wave height H{sub s} estimates. However, for wave energy purposes, the main parameters to be assessed are the wave power P{sub w} and the mean (energy) period T{sub e}. Since P{sub w} is proportional to H{sub s}{sup 2}T{sub e}, its expected error is much larger than for the single-wave parameters. This paper summarizes the intercomparison of two wind-wave models against buoy data in the North Atlantic and the Mediterranean Sea to select the most suitable one for the construction of an Atlas of the wave energy resource in European waters. A full verification in the two basins of ...

1997-08-01

488

A study of the importance of occupancy to building cooling load in prediction by intelligent approach

Land surface parameterization schemes such as the Simple Biosphere Model (SiB2) have found considerable use in climate simulation models, where they provide lower boundary conditions in the form of surface sensible and latent heat fluxes. A methodology is described to apply models of this type at high resolution, using data from the Department of Energy{close_quote}s Cloud and Radiation Testbed in Oklahoma and Kansas, to determine the spatial variations of heat fluxes over the domain and to determine area-weighted flux averages for use in single-column model studies. Data from a dense array of meteorological instruments are interpolated to provide the wind, temperature, vapor pressure, radiation, and precipitation values needed by SiB2. The state of the vegetation is characterized through the use of the normalized difference vegetation index determined from satellites. The ...

1998-03-01

489

Adsorption of carbon tetrachloride on graphitized thermal carbon black and in slit graphitic pores: five-site versus one-site potential models.

Research highlights: #-># The building occupancy affecting the cooling load prediction is studied. #-># PENN model is adopted in this study for predicting the building cooling load. #-># Statistical approach is adopted to result a less prejudice prediction performance. #-># Results show that occupancy data can significantly improve the prediction. -- Abstract: Building cooling load prediction is one of the key factors in the success of energy-saving measures. Many computational models available in the industry today have been developed from either forward or inverse modeling approaches. However, most of these models require extensive computer resources and involve lengthy computation. This paper discusses the use of data-driven intelligent approaches, a probabilistic entropy-based neural (PENN) model to predict the cooling load of a building. ...

2011-07-01

490

Thermal-hydraulic performance of the GETR emergency cooling system: experimental and analytical considerations

The performance of intermolecular potential models on the adsorption of carbon tetrachloride on graphitized thermal carbon black at various temperatures is investigated. This is made possible with the extensive experimental data of Machin and Ross(1), Avgul et al.,(2) and Pierce(3) that cover a wide range of temperatures. The description of all experimental data is only possible with the allowance for the surface mediation. If this were ignored, the grand canonical Monte Carlo (GCMC) simulation results would predict a two-dimensional (2D) transition even at high temperatures, while experimental data shows gradual change in adsorption density with pressure. In general, we find that the intermolecular interaction has to be reduced by 4% whenever particles are within the first layer close to the surface. We also find that this degree of surface mediation is independent of temperature. To understand the packing of carbon tetrachloride in slit ...

2006-05-18

491

Telescope performance near local midnight for the Japanese Advanced Meteorological Imager (JAMI)

The General Electric Test Reactor emergency cooling system performance was tested by intentionally scramming the reactor and then terminating the power to the primary pump. Certain transient thermal-hydraulic data were obtained preceding and during the established natural convection cooling loop composed of the upward flow through the core and the downward flow through the pool. An analysis was performed to permit the data to be extrapolated to obtain distributed fuel element flow rates and bulk temperature rises during the established cooling loop. The earliest time for the quasi-steady natural cooling loop to develop is about 2.5 min following scram. The cladding hot-spot temperature does not exceed the local saturation temperature after quasi-steady flow is established. Data are presented to assist in the modeling of the GETR natural convection loop. Semi-empirical relationships for friction factor and Nusselt number are ...

492

Speed-Sensorless DTC-SVM for Matrix Converter Drives With Simple Non-Linearity Compensation

Raytheon's Santa Barbara Remote Sensing (SBRS) division designed and built the MTSAT-1R Japanese Advanced Meteorological Imager for the Japanese Ministry of Transport between March, 1999 and July, 2002. In order to meet the stressing requirements of a geosynchronous orbit, a combination of structural, thermal, and optical (STOP) analyses were used to design and optimize the beryllium three-mirror anastigmat (TMA) telescope. This modeling approach was used to characterize and minimize the thermal distortion around local midnight. On-orbit temperatures and structural deformations were predicted using thermal Desktop/SINDA and PATRAN/NASTRAN software, respectively. The resulting optical performance was evaluated using Raytheon developed HEXAGON software. The telescope design was successfully optimized to attain specified visible channel performance for most of the 24 hour orbit.

2005-01-01

493

Performance evaluation of multi-fiber optical packet switches

This paper presents a new method to improve sensorless performance of matrix converter drives using a parameter estimation scheme. To improve low-speed sensorless performance, the non-Iinearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching devices, and on-state switching device voltage drop is modelled using PQR transformation and compensated using a reference current control scheme. To eliminate the input current distortion due to the input voltage unbalance, a simple method using PQR transformation is also presented. The proposed compensation method is applied for high performance induction motor drives using a 3 kW matrix converter system without a speed sensor. Experimental results are shown to illustrate the feasibility of the proposed strategy.

2005-01-01

494

British Library Electronic Table of Contents (United Kingdom)

Multi-fiber WDM networks are becoming the major telecommunication platforms for transmitting exponentially increasing data traffic. While today's networks are mainly providing circuit-switched connections, optical packet-switching technologies have been investigated for years, aiming at achieving more efficient utilizations of network resources. In this paper, we have evaluated, for the first time, the packet-loss performance of multi-fiber optical packet switches (MOPS). Our main contributions are threefold. Firstly, we have proposed simple and accurate analytical models for analyzing packet-loss performance of (i) the most fundamental MOPS configuration, (ii) MOPS equipped with fiber delay lines (FDLs) and (iii) shared wavelength converters (SWCs). Secondly, we have shown that the MOPS n...

2007-01-01

495

Influence of Pressurisation on SOFC Performance and Durability: ATheoretical Study

British Library Electronic Table of Contents (United Kingdom)

Abstract Hybrid power plants consisting of a solid oxide fuel cell (SOFC) and a gas turbine show high electrical efficiencies, however require pressurisation of the SOFC to several bar. This paper presents a theoretical investigation of the pressure influence on SOFC performance and durability. A two-dimensional elementary kinetic model is used to predict the performance of a single cell in the pressure range of 1-20-bar. The influence of pressure on thermodynamics, reaction kinetics, porous electrode diffusion, channel transport and efficiency is assessed. It was found that polarisation resistance decreases with increasing pressure due to increased diffusion through porous electrodes and a higher electrode surface coverage with reactant species. Furthermore, open-circuit voltage increases...

2011-01-01

496

Incorporation of organizational failures in PSA

Design of inductive sensors for tongue control system for computers and assistive devices

A large portion of the work performed at nuclear power plants follows standardized flow paths. For example, although components on which the maintenance crew works differ from one assignment to the next, all assignments basically follow the same process: requesting, reviewing, planning, scheduling, executing, testing, and documenting the work. In general, the term open-quotes work processclose quotes is used to refer to a standardized sequence of tasks designed within the operational environment of an organization to achieve a specific goal. The predictable nature of work processes suggests that a systematic analysis can be conducted to identify the desirable design of the process and to develop performance measures with respect to the strengths and weaknesses in the process. Furthermore, because of the close relationship of the work process to plant performance and plant safety, it is believed that such an analysis will ...

1993-06-20

497

British Library Electronic Table of Contents (United Kingdom)

Purpose. The paper introduces a novel design of air-core inductive sensors in printed circuit board (PCB) technology for a tongue control system. The tongue control system provides a quadriplegic person with a keyboard and a joystick type of mouse for interaction with a computer or for control of an assistive device. Method. Activation of inductive sensors was performed with a cylindrical, soft ferromagnetic material (activation unit). Comparative analysis of inductive sensors in PCB technology with existing hand-made inductive sensors was performed with respect to inductance, resistance, and sensitivity to activation when the activation unit was placed in the center of the sensor. Optimisation of the activation unit was performed in a finite element model. Results. PCBs with air-core indu...

2010-01-01

498

Analysis on anomalous degradation in silicon solar cell designed for space use

A trial of probabilistic simulation for reference case in the second progress report on research and development for the geological disposal of HLW in Japan

Recently, we have found the anomalous degradation of electrical performance in silicon solar cells irradiated with charged particles in a high-fluence region. This anomalous phenomenon has two typical features, which are sudden-drop-down of electrical performances in a high-fluence region and slight recovery of the short circuit current I{sub SC} just before the sudden-drop-down. These features cannot be understood by a conventional model coming from the decrease of minority-carriers life-time. We introduce this anomalous degradation of the electrical performance in Si solar cells irradiated with electrons or protons. We also report the result of simulation for the fluence dependence of the I{sub SC}, and discuss the mechanism of this anomalous phenomenon. (author)

1997-03-01

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