WorldWideScience
1

Incremental learning for recognizing handwritten characters using neural networks  

Energy Technology Data Exchange (ETDEWEB)

Artificial Neural Networks (ANNs) are parallel distributed processing machines. The unique characteristics of ANNs are: Fault tolerance, robustness, plasticity and generalization. These offer great potential in many AI applications such as character recognition. Handwritten character recognition is an intrinsically interesting problem, but the difficulties of this task are the many variations in the characters. A robust new incremental learning method, which combines supervised and unsupervised learning paradigms implemented by the Functional Link Net, is illustrated with experimental results. Clustering, based on unsupervised learning, classifies the input data into several categories. The supervised learning paradigm then further classifies the data in the clustered categories.

1989-01-01

2

Visually mediated species and neighbour recognition in fiddler crabs (Uca mjoebergi and Uca capricornis)  

UK PubMed Central (United Kingdom)

Mating signals are often directed at numerous senses and provide information about species identity, gender, receptiveness, individual identity and mate quality. Given the diversity of colourful body...Full Text Available

2006-07-07

3

Surface EMG pattern recognition for real-time control of a wrist exoskeleton  

UK PubMed Central (United Kingdom)

BackgroundSurface electromyography (sEMG) signals have been used in numerous studies for the classification of hand gestures and movements and successfully implemented in the position...Full Text Available

4

A comparison of algorithms for inference and learning in probabilistic graphical models.  

Science.gov (United States)

Research into methods for reasoning under uncertainty is currently one of the most exciting areas of artificial intelligence, largely because it has recently become possible to record, store, and process large amounts of data. While impressive achievements have been made in pattern classification problems such as handwritten character recognition, face detection, speaker identification, and prediction of gene function, it is even more exciting that researchers are on the verge of introducing systems that can perform large-scale combinatorial analyses of data, decomposing the data into interacting components. For example, computational methods for automatic scene analysis are now emerging in the computer vision community. These methods decompose an input image into its constituent objects, lighting conditions, motion patterns, etc. Two of the main challenges are finding effective representations and models in specific applications and finding ...

2005-09-01

5

Impact of Basic Computerized Prescribing on Outpatient Medication Errors and Adverse Drug Events  

UK PubMed Central (United Kingdom)

Few data exist about the impact of computerized prescribing systems on outpatient medication errors (MEs) and adverse drug events (ADEs). We compared the rates of MEs and ADEs in handwritten sites versus...Full Text Available

2002-11-01

6

Efficient higher-order derivatives of the hypergeometric function.  

Energy Technology Data Exchange (ETDEWEB)

Various physics applications involve the computation of the standard hypergeometric function {sub 2}F{sub 1} and its derivatives. Because it is not an intrinsic in the common programming languages, automatic differentiation tools will either differentiate through the code that computes {sub 2}F{sub 1} if that code is available or require the user to provide a hand-written derivative code. We present options for the derivative computation in the context of an ionization problem and compare the approach implemented in the Diamant library to standard methods.

2008-01-01

7

Natural convection cooling of liquid metal systems  

International Nuclear Information System (INIS)

The recognition that natural convection offers the prospect of an important inherent safety feature for liquid metal cooled reactor systems has provided the impetus for a world-wide research effort over the past decade. Whilst this research has been based on experiment, both plant experiments and out-of-pile experiments, the enormous advances in the development of computing power in recent years have enabled complementary programmes of mathematical modelling through numerical simulation of the transport equations in three spatial dimensions. These not only offer considerable promise for the designer in projecting the behaviour from experiments and prototype plant to full scale plant, they have also proved to be of considerable value in helping us to interpret and understand the results of the experiments themselves. This paper attempts to review the progress made with the emphasis on decay heat removal by natural convection in the pool-type ...

8

Exogenous nicotine normalises sensory gating in schizophrenia; therapeutic implications  

British Library Electronic Table of Contents (United Kingdom)

Summary There is a current popular recognition that cigarette smoking is deleterious to health. Although this is very clearly the case for physical health, the situation regarding mental health is, however, rather more complicated. This piece concentrates on the role of smoking in schizophrenia: it is important to consider why schizophrenia, exceptionally amongst the severe and enduring mental illnesses, is associated with increased cigarette consumption. People who suffer from schizophrenia consequently have a greater risk of the complications to physical health caused by this addiction and clearly, it is important to understand why this occurs. Numerous investigators have found that both neuroleptic-naive, first-onset schizophrenics, together with chronic sufferers of the illness, consum...

2009-01-01

9

An application of artificial neural networks in breast cancer recognition using scintimammography  

International Nuclear Information System (INIS)

The aim of the study was to assess the usefulness of artificial neural networks (ANN) application in evaluation of scintimammography in the context of clinical data in the diagnosis of breast cancer. The results produced by ANN were compared with the diagnosis of two independent observers, nuclear medicine specialists. Material and methods: The clinical data and the numerical values derived from scintimammograms of 103 patients were the material for the study. The reference method was the result of histopathology study (core biopsy and /or FNB). Results: The overall sensitivity of physician diagnosis was 78% with specificity of 72%. The ANN produced 71% sensitivity and specificity of 73%. The physicians and ANN results were not significantly different (p=0.4619). Conclusions: Artificial neutral networks are useful tool in clinical diagnosis of breast cancer. (authors)

10

Validation of the 3D finite element transport theory code EVENT for shielding applications  

Energy Technology Data Exchange (ETDEWEB)

This paper is concerned with the validation of the 3D deterministic neutral-particle transport theory code EVENT for shielding applications. The code is based on the finite element-spherical harmonics (FE-P{sub N}) method which has been extensively developed over the last decade. A general multi-group, anisotropic scattering formalism enables the code to address realistic steady state and time dependent, multi-dimensional coupled neutron/gamma radiation transport problems involving high scattering and deep penetration alike. The powerful geometrical flexibility and competitive computational effort makes the code an attractive tool for shielding applications. In recognition of this, EVENT is currently in the process of being adopted by the UK nuclear industry. The theory behind EVENT is described and its numerical implementation is outlined. Numerical results obtained by the code are compared with predictions of the Monte ...

2000-03-01

11

Early detection of damage and analysis of damage development in metal structural components. Schaedigungsfrueherkennung und Schadensablauf bei metallischen Bauteilen  

Energy Technology Data Exchange (ETDEWEB)

The topics of these short lectures on the subject of cyclic stress were: Microstructural mechanisms of damage accumulation under a multistage cyclic stress until incipient cracking; influence of surface decarbonizing phenomena on the failure behaviour of steel construction parts subjected to cyclic stress; thermocyclic fatigue of pipe samples of austenitic steel 1.4436; studies on surface structuring, microstructure and fatigue in LCF area. The short lectures on effects of quasi-static and creep stress were: Shear fracture in AlMg alloys as a result of local plastic instability; study of formation and growth of pores for an early recognition of damage and the course of damage in heat-resistant steels under creep test; experimental and numeric studies of the infuence of the microstructure on the course of damage during shear fractures of steel; numerical modelling of ductile fractures on the basis of micromechanical models. ...

1989-01-01

12

Simultaneous recognition and segmentation of cells: application in C.elegans  

UK PubMed Central (United Kingdom)

Motivation: Automatic recognition of cell identities is critical for quantitative measurement, targeting and manipulation of cells of model animals at single-cell resolution. It has been...Full Text Available

2011-10-15

13

Effects of voicing in the recognition of concurrent syllables (L)a)  

UK PubMed Central (United Kingdom)

This letter reports a study designed to measure the benefits of voicing in the recognition of concurrent syllables. The target and distracter syllables were either voiced or whispered, producing...Full Text Available

2009-12-01

17

Improvement of early recognition of gesture patterns based on a self-organizing map  

British Library Electronic Table of Contents (United Kingdom)

We propose an approach to achieving early recognition of gesture patterns. Early recognition is a method for recognizing sequential patterns at their earliest stage. Therefore, in the case of gesture recognition, we can get a recognition result for human gestures before the gestures are finished. The most difficult problem in early recognition is knowing when the system has determined the result. Most traditional approaches suffer from this problem, since gestures are often ambiguous. At the start of a gesture, in particular, it is very difficult to determinate the recognition result since insufficient input data have been observed. Therefore, we have improved on the traditional approach by using a self-organizing map.

2011-01-01

18

The program HAMILTON for the analytic solution of the equations of motion through fifth order  

International Nuclear Information System (INIS)

HAMILTON is a computer code performing all algebraic operations necessary for an analytic determination of the power series of the Hamiltonian equations of motion in the electromagnetic fields with at least one plane of symmetry. It is written entirely in FORTRAN in order to achieve fast machine performance, a requirement which is essential due to the complexity of the equations of motion in higher orders. HAMILTON is considerably faster than common more versatile formula manipulators and uses noticeably less storage. Besides the mere solution of the equations of motion, HAMILTON also produces FORTRAN code compatible with the program COSY 5.0 allowing the computation of matrix elements of individual optical elements and their concatenation. The produced FORTRAN code is highly optimized and on average requires only 30% of the execution time of a handwritten comparable code. (orig.).

19

Distinguishing three levels in explicit self-awareness  

British Library Electronic Table of Contents (United Kingdom)

This paper focuses on the development of explicit self-awareness in children. Mirror self-recognition has been the most popular paradigm used to assess this ability in children. Nevertheless, according to Rochat (2003), there are, at least, three different levels of explicit self-awareness. We therefore designed three different self-recognition tasks, each corresponding to one of these levels (a mirror self-recognition task, a picture self-recognition task and a masked self-recognition task). We observed a decrease in performance across the three tasks. This supports a developmental scale in self-awareness. Besides, the masked self-recognition performance makes it possible to assess the final and the most sophisticated level of self-awareness, i.e. the external self. To our best knowledge,...

2011-01-01

20

Task-Specific Codes for Face Recognition: How they Shape the Neural Representation of Features for Detection and Individuation  

UK PubMed Central (United Kingdom)

BackgroundThe variety of ways in which faces are categorized makes face recognition challenging for both synthetic and biological vision systems. Here we focus on two face processing...Full Text Available

21

Structural Basis for Acetylated Histone H4 Recognition by the Human BRD2 Bromodomain*  

UK PubMed Central (United Kingdom)

Recognition of acetylated chromatin by the bromodomains and extra-terminal domain (BET) family proteins is a hallmark for transcriptional activation and anchoring viral genomes to mitotic chromosomes...Full Text Available

2010-03-05

22

Relative threat and recognition ability in the responses of tropical mockingbirds to song playback  

UK PubMed Central (United Kingdom)

It has been suggested that individual recognition based on song may be constrained by repertoire size in songbirds with very large song repertoires. This hypothesis has been difficult to test...Full Text Available

2007-04-01

23

Noise Susceptibility of Cochlear Implant Users: The Role of Spectral Resolution and Smearing  

UK PubMed Central (United Kingdom)

The latest-generation cochlear implant devices provide many deaf patients with good speech recognition in quiet listening conditions. However, speech recognition deteriorates rapidly as the level of...Full Text Available

2005-03-01

24

Fungal recognition is mediated by the association of dectin-1 and galectin-3 in macrophages  

UK PubMed Central (United Kingdom)

Dectin-1, the major β-glucan receptor in leukocytes, triggers an effective immune response upon fungal recognition. Here we use sortase-mediated transpeptidation, a technique that allows placement...Full Text Available

2011-08-23

25

Differential recognition of viral RNA by RIG-I  

UK PubMed Central (United Kingdom)

Retinoic acid inducible gene I (RIG-I) is a pattern recognition receptor (PRR) responsible for detection of nucleic acids from pathogens in the cytoplasm of infected cells and induction of type I interferon...Full Text Available

2011-03-01

26

Dengue virus protein recognition by virus-specific murine CD8+ cytotoxic T lymphocytes.  

UK PubMed Central (United Kingdom)

The identification of the protein targets for dengue virus-specific T lymphocytes may be useful for planning the development of subunit vaccines against dengue. We studied the recognition by murine...Full Text Available

1993-02-01

27

A global optimization algorithm for protein surface alignment  

UK PubMed Central (United Kingdom)

BackgroundA relevant problem in drug design is the comparison and recognition of protein binding sites. Binding sites recognition is generally based on geometry often combined with...Full Text Available

28

System integration of pattern recognition, adaptive aided, upper limb prostheses  

Science.gov (United States)

The requirements for successful integration of a computer aided control system for multi degree of

1975-01-01

31

An Integrated Approach to Intelligent Systems  

Science.gov (United States)

... order probabilistic modelling, multisensor monitoring of ... object recognition, image registration and point ... of the Berkeley Continuous Media Toolkit. ...

2002-01-01

32

Anomalous zones in Gulf Coast Salt domes with special reference to Big Hill, TX, and Weeks Island, LA  

Energy Technology Data Exchange (ETDEWEB)

Anomalous features in Gulf Coast Salt domes exhibit deviations from normally pure salt and vary widely in form from one dome to the next, ranging considerably in length and width. They have affected both conventional and solution mining in several ways. Gas outbursts, insolubles, and potash (especially carnallite) have led to the breakage of tubing in a number of caverns, and caused irregular shapes of many caverns through preferential leaching. Such anomalous features essentially have limited the lateral extent of conventional mining at several salt mines, and led to accidents and even the closing of several other mines. Such anomalous features, are often aligned in anomalous zones, and appear to be related to diapiric processes of salt dome development. Evidence indicates that anomalous zones are found between salt spines, where the differential salt intrusion accumulates other materials: Anhydrite bands which are relatively strong, and other, weaker impurities. Shear zones and fault ...

1993-07-01

33

Local binary pattern based features for sign language recognition  

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

34

Coreference and Lexical Repetition: Mechanisms of Discourse Integration  

UK PubMed Central (United Kingdom)

The use of repeated expressions to establish coreference allows an investigation of the relationship between basic processes of word recognition and higher-level...Full Text Available

2007-06-01

35

Interactions between tRNA identity nucleotides and their recognition sites in glutaminyl-tRNA synthetase determine the cognate amino acid affinity of the enzyme.  

UK PubMed Central (United Kingdom)

Sequence-specific interactions between aminoacyl-tRNA synthetases and their cognate tRNAs both ensure accurate RNA recognition and prevent the binding of noncognate substrates. Here we show for Escherichia...Full Text Available

1996-07-09

36

[Improvement of the recognition probability about camouflage target based on BP neural network].  

Science.gov (United States)

Using static Michelson interferometer to get the spectrum information of measurement targets for spectrum identification, under the condition that the interference length is constant, the system can be optimized by BP neural network algorithm for the mixed spectral separation process. Thereby it can realize improving the recognition probability of camouflage target. Collecting the spectrum information in field of view (FOV) by the interferometer and linear array CCD detector, composing the set of mixed spectrum data, with known absorption spectrum of the material as a hidden layer of rules, it used BP neural network to separate the mixed spectrum data. Experiment with different distances, different combinations of mixed background spectrum as the initial data, using steel target (size: 1.5 m x 1.5 m) made of four kinds, the recognition probability of non-camouflage target is about 90% by BP neural network algorithm or the traditional algorithm, ...

2010-12-01

37

Void signal analysis and gas-liquid two-phase flow regime determination by a statistical pattern recognition method  

International Nuclear Information System (INIS)

A statistical pattern recognition method was applied to the analysis of the signals of crosssectional mean void fraction for discriminating gas-liquid two-phase flow regimes. The analysis and discrimination were carried out based on six key flow patterns : bubble, cap-bubble, plug, froth (F_I and F_I_I), and annular flow. For each flow condition 100 void signals with a recording dimension of 1 second were used and transferred to discrete data, the sampling frequency of which was selected at 100 Hz by comparison between correct recognition rates obtained from different frequencies. The magnitude of the time-averaged void fraction was partly employed supplementary to the pattern recognition method. The boundaries between the six flow regimes were determined corresponding to a correct recognition rate of 80 % and drawn on a superficial gas-liquid velocities diagram. These flow boundaries were also compared ...

1986-01-01

38

Medium voltage network planning based on probabilistic reliability evaluation including the insurance system  

Energy Technology Data Exchange (ETDEWEB)

In comparison to deterministic criteria, probabilistic reliability indices like interruption frequency and unavailability give a more differentiated insight into reliability in an electrical energy network. One possibility for network planning based on these indices is the definition of limits for customer nodes, another is the monetarisation of reliability in terms of interruption costs. Because of numerous disadvantages, interruption cost methods could not up to now win broad recognition in network planning in Western Europe. A more recent method for the monetarisation of reliability circumventing most of these disadvantages is the insurance system. In this system the customer selects a tariff class in an insurance system, and the utility reimburses its customers in the case of an interruption. In its first section, the paper describes a method for the flexible and realistic optimisation of MV networks. This method based on Genetic ...

1997-07-01

39

Modular Traffic Sign Recognition applied to on-vehicle real-time visual detection of American and European speed limit signs  

CERN Document Server

We present a new modular traffic signs recognition system, successfully applied to both American and European speed limit signs. Our sign detection step is based only on shape-detection (rectangles or circles). This enables it to work on grayscale images, contrary to most European competitors, which eases robustness to illumination conditions (notably night operation). Speed sign candidates are classified (or rejected) by segmenting potential digits inside them (which is rather original and has several advantages), and then applying a neural digit recognition. The global detection rate is ~90% for both (standard) U.S. and E.U. speed signs, with a misclassification rate 150 minutes of video. The system processes in real-time ~20 frames/s on a standard high-end laptop.

2009-01-01

40

Model-based fuzzy control of power system static/dynamic security using the pattern recognition approach  

Energy Technology Data Exchange (ETDEWEB)

Using databases derived from the pattern recognition approach, the paper presents a methodology for utilizing fuzzy models to enhance the quality of decision-making using fuzzy-logic algorithms. Two multi-objective fuzzy-logic control algorithms for controlling power system static/dynamic security are presented and analyzed. The first algorithm is based on the successive inferences of fuzzy implication rules for each individual objective, and the second algorithm is an application of the method of fuzzy linear programming. The paper discusses the properties, advantages and limitations of applying fuzzy decision-making logic in the pattern-recognition approach and concludes by highlighting potential areas for further development. (author)

1994-07-01

43

Uracil-DNA glycosylase: Structural, thermodynamic and kinetic aspects of lesion search and recognition  

UK PubMed Central (United Kingdom)

Uracil appears in DNA as a result of cytosine deamination and by incorporation from the dUTP pool. As potentially mutagenic and deleterious for cell regulation, uracil must be removed from DNA....Full Text Available

2010-03-01

44

Transient Hoogsteen Base Pairs in Canonical Duplex DNA  

UK PubMed Central (United Kingdom)

Sequence-directed variations in the canonical DNA double helix structure that retain Watson-Crick base-pairing play important roles in DNA recognition, topology, and nucleosome positioning....Full Text Available

2011-02-24

45

The feasibility of using pattern recognition software to measure the influence of computer use on the consultation  

UK PubMed Central (United Kingdom)

BackgroundA key feature of a good general practice consultation is that it is patient-centred. A number of verbal and non-verbal behaviours have been identified as important to establish...Full Text Available

46

Structure of Natural Killer Cell Receptor KLRG1 Bound to E-Cadherin Reveals Basis for MHC-Independent Missing Self Recognition  

UK PubMed Central (United Kingdom)

SUMMARYThe cytolytic activity of natural killer (NK) cells is regulated by inhibitory receptors that detect the absence of self molecules on target cells. Structural studies of...Full Text Available

2009-07-17

47

Structural and Functional Insights into Saccharomyces cerevisiae Tpa1, a Putative Prolylhydroxylase Influencing Translation Termination and Transcription*  

UK PubMed Central (United Kingdom)

Efficiency of translation termination relies on the specific recognition of the three stop codons by the eukaryotic translation termination factor eRF1. To date only a few proteins are known to be involved...Full Text Available

2010-10-01

48

Recognition of historic influenza epidemics from parish burial records: a test of prediction from a new hypothesis of influenzal epidemiology.  

UK PubMed Central (United Kingdom)

On the current conception of the epidemiology of epidemic influenza, as caused by a mechanism of direct spread of the virus from the sick, epidemics must have travelled much more slowly in former times...Full Text Available

1983-10-01

49

Recognition of Dual or Multiple Pathology in Skin Biopsies from Patients with HIV/AIDS  

UK PubMed Central (United Kingdom)

A large percentage of patients with HIV/AIDS will develop dermatological complications. Consequently, all practising clinicians and pathologists in regions with a high prevalence of HIV/AIDS must be...Full Text Available

50

Rapid Onset of Maternal Vocal Recognition in a Colonially Breeding Mammal, the Australian Sea Lion  

UK PubMed Central (United Kingdom)

BackgroundIn many gregarious mammals, mothers and offspring have developed the abilities to recognise each other using acoustic signals. Such capacity may develop at different rates...Full Text Available

51

RNA recognition by the embryonic cell fate determinant and germline totipotency factor MEX-3  

UK PubMed Central (United Kingdom)

Totipotent stem cells have the potential to differentiate into every cell type. Renewal of totipotent stem cells in the germline and cellular differentiation during early embryogenesis rely upon posttranscriptional...Full Text Available

2009-12-01

52

RIN4-like proteins mediate resistance protein-derived soybean defense against Pseudomonas syringae  

UK PubMed Central (United Kingdom)

Resistance (R) protein mediated recognition of pathogen avirulence effectors triggers signaling that induces a very robust form of species-specific immunity in plants. The soybean Rpg1-b protein mediates...Full Text Available

2010-11-01

53

Queen's discovery lauded by top scientific journal  

CERN Multimedia

A scientific breakthrough at Queen's University's Sudbury Neutrino Observatory has received major international recognition. The journal Science ranked the discovery that cracked the "neutrino problem" second, in the journal's top 10 scientific achievements of 2002 (1/2 page).

2002-01-01

54

Psychodynamic Experience Enhances Recognition of Hidden Childhood Trauma  

UK PubMed Central (United Kingdom)

BackgroundExperimental psychology has only recently provided supporting evidence for Freud's and Janet's description of unconscious phenomena. Here, we aimed to assess whether specific...Full Text Available

55

Polymorphisms in IRF7 reduce IFN? responses of pDCs to HIV-1  

UK PubMed Central (United Kingdom)

Recognition of HIV-1 ssRNA by TLR7 induces the production of the pro-inflammatory cytokines that may contribute to the systemic immune activation associated with HIV-1 disease progression. Here...Full Text Available

2011-03-13

56

Perceptual Simulations and Linguistic Representations Have Differential Effects on Speeded Relatedness Judgments and Recognition Memory  

UK PubMed Central (United Kingdom)

We examined the effect of spatial iconicity (a perceptual simulation of canonical locations of objects) and word-order frequency on language processing and episodic memory of orientation. Participants...Full Text Available

2010-05-01

57

Perceived association between diagnostic and non-diagnostic cues of women's sexual interest: General Recognition Theory predictors of risk for sexual coercion  

UK PubMed Central (United Kingdom)

Young men's errors in sexual perception have been linked to sexual coercion. The current investigation sought to explicate the perceptual and decisional sources of these social perception errors,...Full Text Available

2010-01-01

58

Orp1, a member of the Cdc18/Cdc6 family of S-phase regulators, is homologous to a component of the origin recognition complex.  

UK PubMed Central (United Kingdom)

cdc18+ of Schizosaccharomyces pombe is a periodically expressed gene that is required for entry into S phase and for the coordination of S phase with mitosis. cdc18+ is related to the Saccharomyces...Full Text Available

1995-12-19

59

Involvement of the Matrix and Nucleocapsid Domains of the Bovine Leukemia Virus Gag Polyprotein Precursor in Viral RNA Packaging  

UK PubMed Central (United Kingdom)

The RNA packaging process for retroviruses involves a recognition event of the genome-length viral RNA by the viral Gag polyprotein precursor (PrGag), an important step in particle morphogenesis. The...Full Text Available

2003-09-01

60

Identification of the Neoplastically Transformed Cells in Marek's Disease Herpesvirus-Induced Lymphomas: Recognition by the Monoclonal Antibody AV37  

UK PubMed Central (United Kingdom)

Understanding the interactions between herpesviruses and their host cells and also the interactions between neoplastically transformed cells and the host immune system is fundamental to understanding...Full Text Available

2002-07-01

61

Human Pol II promoter recognition based on primary sequences and free energy of dinucleotides  

UK PubMed Central (United Kingdom)

BackgroundPromoter region plays an important role in determining where the transcription of a particular gene should be initiated. Computational prediction of eukaryotic Pol II promoter...Full Text Available

62

Frequency-domain analysis of sound pressure oscillation in natural convective subcooled boiling system and its regime recognition  

International Nuclear Information System (INIS)

The dynamical signals of sound pressure oscillation in natural convective subcooled boiling system are obtained by using computer data acquisition technique. Through frequency-domain analysis of typical dynamical data, combined with study on the acquired time series of sound pressure, are observed and explained. The time-frequency phenomena, such as the onset of shock wave, frequency doubling relation of sound pressure, combination of sound frequency spectrum peaks etc., which describe the characteristics of natural convective subcooled boiling system are presented. Furthermore, based on frequency spectra of sound pressure, related eigen vectors are defined and established and with dynamical clustering method, regime recognition for the dynamical process of system is carried out. Results of recognition are consistent with that of qualitative analysis of time series, which is of great significance for automatic monitoring system of nuclear ...

1998-12-01

63

Evidence of Segregated Spawning in a Single Marine Fish Stock: Sympatric Divergence of Ecotypes in Icelandic Cod?  

UK PubMed Central (United Kingdom)

There is increasing recognition of intraspecific diversity and population structure within marine fish species, yet there is little direct evidence of the isolating mechanisms that maintain it or documentation...Full Text Available

64

EphB Receptors Couple Dendritic Filopodia Motility to Synapse Formation  

UK PubMed Central (United Kingdom)

SUMMARYMotile dendritic filopodial processes are thought to be precursors of spine synapses, but how motility relates to cell-surface cues required for axon-dendrite recognition...Full Text Available

2008-07-10

65

Enantioselective Fluorescent Recognition of Chiral Acids by Cyclohexane-1,2-diamine-Based Bisbinaphthyl Molecules  

UK PubMed Central (United Kingdom)

The cyclohexane-1,2-diamine-based bisbinaphthyl macrocycles (S)-/(R)-5 and their cyclic and acyclic analogs are synthesized. The interactions of...Full Text Available

2007-06-22

66

Effect of clindamycin on neutrophil killing of gram-negative periodontal bacteria.  

UK PubMed Central (United Kingdom)

Periodontal diseases are infections of the tissues supporting the dentition. Recognition that relatively specific microfloras are associated with distinct clinical forms of periodontal disease has prompted...Full Text Available

1988-10-01

67

Effect of atypical antibiotic resistance on microorganism identification by pattern recognition.  

UK PubMed Central (United Kingdom)

We classified microorganisms from the clinical laboratory by using information provided by the Gram stain and antibiotic sensitivity profiles obtained with the Bauer-Kirby technique. Approximately 4,000...Full Text Available

1978-12-01

68

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

Science.gov (United States)

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 ...

2011-04-01

69

Differential targeting of Tetrahymena ORC to ribosomal DNA and non-rDNA replication origins  

UK PubMed Central (United Kingdom)

The Tetrahymena thermophila origin recognition complex (ORC) contains an integral RNA subunit, 26T RNA, which confers specificity to the amplified ribosomal DNA (rDNA) origin by base...Full Text Available

2009-02-04

70

Current practices in spatial analysis of cancer data: data characteristics and data sources for geographic studies of cancer  

UK PubMed Central (United Kingdom)

The use of spatially referenced data in cancer studies is gaining in prominence, fueled by the development and availability of spatial analytic tools and the broadening recognition of the linkages between...Full Text Available

71

Counselling in an inner city general practice: analysis of its use and uptake.  

UK PubMed Central (United Kingdom)

BACKGROUND. In recognition of the emotional problems which frequently underlie somatic complaints, practices increasingly offer counselling as part of their services to patients. In an inner city practice,...Full Text Available

1994-04-01

72

Construction of DNA recognition sites active in Haemophilus transformation.  

UK PubMed Central (United Kingdom)

Competent Haemophilus cells recognize and preferentially take up Haemophilus DNA during genetic transformation. This preferential uptake is correlated with the presence on incoming DNA of an 11-base-pair...Full Text Available

1982-04-01

73

Computational promoter analysis of mouse, rat and human antimicrobial peptide-coding genes  

UK PubMed Central (United Kingdom)

BackgroundMammalian antimicrobial peptides (AMPs) are effectors of the innate immune response. A multitude of signals coming from pathways of mammalian pathogen/pattern recognition...Full Text Available

74

Antagonist HIV-1 Gag Peptides Induce Structural Changes in HLA B8  

UK PubMed Central (United Kingdom)

In the cellular immune response, recognition by CTL-TCRs of viral antigens presented as peptides by HLA class I molecules, triggers destruction of the virally infected cell (Townsend, A.R.M., J. Rothbard,...Full Text Available

1996-12-01

75

A Novel Form of Transcriptional Silencing by Sum1-1 Requires Hst1 and the Origin Recognition Complex  

UK PubMed Central (United Kingdom)

In the yeast Saccharomyces cerevisiae, a and α mating-type information is stored in transcriptionally silenced cassettes called HML and HMR....Full Text Available

2001-05-01

76

Development of a motion analysis system using acceleration sensors for tennis and its evaluations  

British Library Electronic Table of Contents (United Kingdom)

The term biological motion is often used by researchers studying the patterns of movement generated by living forms and in sports. We studied a pattern recognition system of motion in sport using biological motion data. Biological motion data are acquired using a 3D motion capture system. However, 3D motion capture systems are very expensive. In this article, a biological motion capture system was built using acceleration sensors. Our proposed system uses the technique of Gaussian fitting and regression analysis. We tested our proposed system in pattern recognition of outdoor tennis and its evaluations.

2011-01-01

77

Atomic substitution reveals the structural basis for substrate adenine recognition and removal by adenine DNA glycosylase  

Science.gov (United States)

Adenine DNA glycosylase catalyzes the glycolytic removal of adenine from the promutagenic A {center_dot} oxoG base pair in DNA. The general features of DNA recognition by an adenine DNA glycosylase, Bacillus stearothermophilus MutY, have previously been revealed via the X-ray structure of a catalytically inactive mutant protein bound to an A:oxoG-containing DNA duplex. Although the structure revealed the substrate adenine to be, as expected, extruded from the DNA helix and inserted into an extrahelical active site pocket on the enzyme, the substrate adenine engaged in no direct contacts with active site residues. This feature was paradoxical, because other glycosylases have been observed to engage their substrates primarily through direct contacts. The lack of direct contacts in the case of MutY suggested that either MutY uses a distinctive logic for substrate recognition or that the X-ray structure had captured a noncatalytically competent ...

2010-01-14

78

One-class classifiers and their application to synthetic aperture radar target recognition  

Energy Technology Data Exchange (ETDEWEB)

Target recognition requires the ability to distinguish targets from non-targets, a capability called one-class generalization. To function as a one-class classifier, a neural network must have three types of generalization: within-class, between-class, and out-of-class. We discuss these three types of generalization and identify neural network architectures that meet these requirements. We have applied our one-class classifier ideas to the problem of automatic target recognition in synthetic aperture radar. We have compared three neural network algorithms: Carpenter and Grossberg`s algorithmic version of the Adaptive Resonance Theory (ART-2A), Kohonen`s Learning Vector Quantization (LVQ), and Reilly and Cooper`s Restricted Columb Energy network (RCE). The ART 2-A neural network has given the best results, with 100% within-class, and out-of-class generalization. Experiments show that the network`s performance is sensitive to vigilance and number ...

1992-10-01

79

One-class classifier networks for target recognition applications  

Energy Technology Data Exchange (ETDEWEB)

Target recognition requires the ability to distinguish targets from non-targets, a capability called one-class generalization. Many neural network pattern classifiers fail as one-class classifiers because they use open decision boundaries. To function as one-class classifier, a neural network must have three types of generalization: within-class, between-class, and out-of-class. We discuss these three types of generalization and identify neural network architectures that meet these requirements. We have applied our one-class classifier ideas to the problem of automatic target recognition in synthetic aperture radar. We have compared three neural network algorithms: Carpenter and Grossberg`s algorithmic version of the Adaptive Resonance Theory (ART-2A), Kohonen`s Learning Vector Quantization (LVQ), and Reilly and Cooper`s Restricted Coulomb Energy network (RCE). The ART 2-A neural network gives the best results, with 100% within-class, ...

1993-01-01

80

Artificial receptor for peptide recognition in protic media: The role of metal ion coordination  

International Nuclear Information System (INIS)

The production of molecularly imprinted polymers (MIPs) for the recognition of C-terminal cholecystokinin pentapeptide (CCK-5) in the presence of metal ion is reported. The MIPs were produced under the same molar ratio of template to monomers (acrylamide, N,N'-methylene bisacrylamide) in the presence or absence of nitrilotriacetic acid-nickel (Ni-NTA) complex. Scanning electron microscopy images of MIPs were obtained in an attempt to correlate the adsorption characteristics with polymer's morphology. Subsequently Ni2+ was removed and substituted by other divalent ions such as Mg2+, Fe2+, Zn2+, Co2+ and Cu2+. It was found that polymers containing the metal ion complex with the order Fe-NTA, Ni-NTA and Cu-NTA presented lower dissociation constant values than the rest thus exhibiting stronger guest binding activity. The percentage of theoretical maximum binding sites Bmax was almost the same for these ions, indicating that the ion-template coordination is responsible ...

2008-08-25

81

Active SWD using monochromatic source wavelet; Tan`itsu shuhasu no shingen hakei wo mochiita active SWD  

Energy Technology Data Exchange (ETDEWEB)

As part of developing efforts for physical exploration technologies for oil reservoirs, this paper describes development of an active seismic while drilling (SWD). The SWD is a seismic exploration method to acquire records equivalent to VSP using seismic waves generated from a bit executing excavation, and is capable of detection and control on a real time basis during the excavation. However, the drawback is that it is subjected to a limitation in the bit. To eliminate this limitation, an artificial seismic source method was devised. In other words, this is an SWD utilizing an artificial seismic source. The contrivance is such that a shot sub containing a magnetic distortion oscillator is attached directly above a bit to generate vibration artificially, and try to utilize larger seismic energy by combining this vibration with that generated from the excavating bit. Frequency band in the seismic source is as narrow as nearly a single frequency waveform. Preparing a time-depth curve ...

1997-05-27

82

Update on Waterjet Cutting: How CNCs (Computer Numerical ...  

Science.gov (United States)

... Accession Number : ADD802897. Title : Update on Waterjet Cutting: How CNCs (Computer Numerical Controls) Are Turning the Tide. ...

83

The Numerical Weather Prediction System at the Italian Air ...  

Science.gov (United States)

... Title : The Numerical Weather Prediction System at the Italian Air Force Weather Service: Impact of Non-Conventional Observations and Increased ...

2004-06-01

84

Numerical Weather Prediction and Synoptic Meteorology.  

Science.gov (United States)

The report gives a summary of important developments in numerical weather prediction and discusses their relationship to, and effect on, the practice of synoptic meteorology.

1968-01-01

85

Training And Education Needs In Radiological Protection - First Results Of The ENETRAP Survey  

Energy Technology Data Exchange (ETDEWEB)

Recent studies have shown that there is a wide variety of approaches to education and training of the Qualified Expert across the European Union. National education and training programmes show often large differences in content, duration, level, the introduction of practical work, etc. As they stand, such differences are a barrier to the mutual recognition of the Qualified Expert status and, in part, are contributing to a perceived shortage in expertise in radiation protection and safety. The overall aim of ENETRAP is to determine mechanisms that in the longer term will facilitate better integration of education and training activities (with a view to mutual recognition across the European Union) and to ensure the ongoing provision of the necessary competence and expertise at the level of the Qualified Expert. The ENETRAP project is a 6FP coordination action. It started in April 2005 and runs over a period of 24 months. (authors)

2006-07-01

86

Quantum probabilities: an information-theoretic interpretation  

CERN Document Server

This Chapter develops a realist information-theoretic interpretation of the nonclassical features of quantum probabilities. On this view, what is fundamental in the transition from classical to quantum physics is the recognition that \\emph{information in the physical sense has new structural features}, just as the transition from classical to relativistic physics rests on the recognition that space-time is structurally different than we thought. Hilbert space, the event space of quantum systems, is interpreted as a kinematic (i.e., pre-dynamic) framework for an indeterministic physics, in the sense that the geometric structure of Hilbert space imposes objective probabilistic or information-theoretic constraints on correlations between events, just as the geometric structure of Minkowski space in special relativity imposes spatio-temporal kinematic constraints on events. The interpretation of quantum probabilities is more subjectivist in spirit ...

2010-01-01

87

Preparation and pattern recognition of O'-sialon by reduction-nitridation from coal gangue  

International Nuclear Information System (INIS)

The phase composition and microstructure of O'-sialon prepared from Chinese coal gangue have been studied. The use of Si powder is more effective than that of activated carbon or mainly carbon with a little silicon for reduction-nitridation. For specimens with 40% Si addition, more than 80% of O'-sialon may be obtained when nitrided at 1500 degree sign C. The formed O'-sialon was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The parameters for O'-Sialon preparation are optimized by computer pattern recognition program based on principal component analysis, the target parameter optimum regions with higher relative content of O'-Sialon was indicated by this way.

2004-11-15

88

Fault diagnosis of roller bearing using fuzzy classifier and histogram features with focus on automatic rule learning  

British Library Electronic Table of Contents (United Kingdom)

Roller bearing is one of the most widely used elements in rotary machines. Condition monitoring of such elements is conceived as pattern recognition problem. Pattern recognition has three main phases: feature extraction, feature selection and feature classification. Histogram features can be used for fault diagnosis of roller bearing. This paper presents the use of decision tree for selecting best few histogram features (bin ranges) that will discriminate the fault conditions of the bearing from given train samples. These features are extracted from vibration signals. A rule set is formed from the extracted features and fed to a fuzzy classifier. The rule set necessary for building the fuzzy classifier is obtained largely by intuition and domain knowledge. This paper also presents the usag...

2011-01-01

89

A playmate robot system for playing the rock-paper-scissors game with humans  

British Library Electronic Table of Contents (United Kingdom)

We have developed a playmate robot system for playing the rock-paper-scissors game with humans. The playmate robot recognizes the hand motions of a human using image processing without attaching any additional units to the human. The playmate robot system consists of three parts: a game management part, a hand motion recognition part, and a robot hand control part. The system functions as follows. (1) Before the game is played, the game management part decides on the motion of the robot hand from amongst rock, paper, and scissors. After the game is played, the robot develops a reaction using speech and facial expressions depending on the result of the game. (2) The hand motion recognition part recognizes the hand motion of the human. It does not use any additional units on the human?s body...

2011-01-01

92

Numerical Optimization  

Science.gov (United States)

... been possible to prove the existence and uniqueness of a classical solution which tends to the well-known solution of the Stefan problem as the ...

1989-01-01

101

Sur l'origine des chiffres arabes  

CERN Document Server

Sur l'origine des chiffres arabes A. Boucenna 1 From the pagination of an Algerian Arabic manuscript of the beginning of the 19th century,we rediscover the original shape that the Arabic numerals had before passing in Europe and underwent the transformation that gave the modern Arabic numerals. This original shape,whose use disappeared completely, proves that these numerals have their origin in the Arabic letters. Contrary to what some hypotheses pretend, particularly those that present them as drifting of Indian characters, the 10 Arabic numerals that we use are, nothing else, 10 Arabic letters more or less modified and taken in the "Abjadi" order. The hypothesis of the Indian origin of the Arabic numerals is revealed a mistake denied by the shape of the Arabic numerals and by the logic of the right to left representation of the numbers and the algorithm of the ...

2003-01-01

102

Zinc/air technology, December 1993 meeting report  

Energy Technology Data Exchange (ETDEWEB)

A Zinc/Air Battery Review and Strategic Planning Meeting was held in 1993. One outcome of the meeting was recognition of the need for a report on the current status of the technology. This report contains contributions from many of the attendees at the above meeting and expresses their views on where the technology is today and what could/should be done to improve its performance.

1994-10-01

103

The k43 gene, required for chorion gene amplification and diploid cell chromosome replication, encodes the Drosophila homolog of yeast origin recognition complex subunit 2  

UK PubMed Central (United Kingdom)

Lethal alleles of the Drosophila k43 gene result in small or missing imaginal discs, greatly reduced mitotic index, and fragmented and abnormally condensed chromosomes. A female-sterile...Full Text Available

1997-04-15

104

Synthesis and cloning of the genes of antisense peptides of human calcitonin and miniproinsulin  

Energy Technology Data Exchange (ETDEWEB)

With the aim of an experimental check on the validity of the theory of molecular recognition, the authors have carried out the chemical-enzymatic synthesis and cloning of the gene of human calcitonin and also of the genes of antisense polypeptides to human calcitonin and miniproinsulin. It has been shown that recombinant plasmids obtained on the basis of these synthetic genes are capable of ensuring the biosynthesis of the given polypeptides in E. coli cells as hybrid proteins with the IgG-binding domain of staphylococcal protein A.

1994-07-20

105

Structural Chemistry of Human SET Domain Protein Methyltransferases  

Science.gov (United States)

There are about fifty SET domain protein methyltransferases (PMTs) in the human genome, that transfer a methyl group from S-adenosyl-L-methionine (SAM) to substrate lysines on histone tails or other peptides. A number of structures in complex with cofactor, substrate, or inhibitors revealed the mechanisms of substrate recognition, methylation state specificity, and chemical inhibition. Based on these structures, we review the structural chemistry of SET domain PMTs, and propose general concepts towards the development of selective inhibitors.

2011-08-22

106

Process optimization for saccharification of cellulose by acid hydrolysis  

Energy Technology Data Exchange (ETDEWEB)

Cellulose raw materials costs must be considered in order to obtain a minimized hexose cost. In recognition of this fact, it may be economically advantageous to operate at less than maximum hexose concentration in the reactor and to recycle unreacted cellulose. The objective of this article is to optimize a cellulose-recycle reactor system for producing hexose at minimum cost. A sensitivity analysis of the important variables in the mathematical model of this system is also discussed.

1980-01-01

107

New 'prime mover' for electric cars  

Energy Technology Data Exchange (ETDEWEB)

Electric cars are a clean and noiseless alternative to vehicles with combustion engines for journeys in cities and their environs. In recognition of this, ABB has developed an efficient electric drive system featuring modern power electronics and a high-energy, sodium-sulphur battery. The energy-to-weight ratio of this battery is four times that achieved with conventional lead-acid batteries. To recharge the battery, a charger mounted next to the motor has only to be connected to a household power socket.

1989-01-01

108

Molecular recognition of nitrated fatty acids by PPAR[gamma  

Energy Technology Data Exchange (ETDEWEB)

Peroxisome proliferator activated receptor-{gamma} (PPAR{gamma}) regulates metabolic homeostasis and adipocyte differentiation, and it is activated by oxidized and nitrated fatty acids. Here we report the crystal structure of the PPAR{gamma} ligand binding domain bound to nitrated linoleic acid, a potent endogenous ligand of PPAR{gamma}. Structural and functional studies of receptor-ligand interactions reveal the molecular basis of PPAR{gamma} discrimination of various naturally occurring fatty acid derivatives.

2010-03-08

109

Knowledge-based image analysis: some aspects on the analysis of images using other types of information  

Energy Technology Data Exchange (ETDEWEB)

The computer vision approach to image analysis is discussed from two aspects. First, this approach is constrasted to the pattern recognition approach. Second, how external knowledge and information and models from other fields of science and engineering can be used for image and scene analysis is discussed. In particular, the connections between computer vision and computer graphics are pointed out.

1982-01-01

110

Increased renal corticomedullary FDG activity in a patient of NHL-malignant or benign?  

International Nuclear Information System (INIS)

Authors describe diagnostic dilemma of differentiating pyelonephritis with lymphomatous involvement of kidney in a known case of lymphoma. FDG uptake pattern was non-discriminatory and pyelonephritis diagnosed retrospectively on follow up study. Authors emphasize the importance of recognition of features and subtle clues of infection evident on CT component of PET-CT. (author)

111

Harmful Algae, Nuisance Blooms and Anthropogenic Nutrient Enrichment  

Environmental Research Database

DescriptionPhytoplankton is the collective name given to the microscopic floating plants in seas and lakes. Under certain conditions, the abundance of phytoplankton as a whole or of one or more species in particular, can reach a magnitude at which it is visible through discolouration of the sea. Some of these blooms because of the colour of the water have been called 'Red Tides'. Blooms of some 300 species of the phytoplankton are known as Harmful Algal Bloom (HAB) species in recognition of their poten [continued...

2009-01-31

112

Face recognition based on color model  

Science.gov (United States)

Over the past ten years face segmentation has developed rapidly and various algorithms have been proposed. In this paper we will demonstrate a face detection system based on skin color and the spaces RGB, normalized RGB, HSV and YCbCr are concentrated here. Through combing them the more accurate face region will be detected.

2011-04-01

113

Evaluate the Health Potential of Fruit & Vegetable Snack Products (EFH 11)  

Environmental Research Database

DescriptionDespite the growing recognition of the important part fruit and vegetables can play in helping prevent a number of diseases, health and nutrition experts are concerned about the low consumption of fruits and vegetables in the UK. The principal aim of this project is to improve consumer dietary consumption of fruit and vegetables by developing novel snack foods based on the fruit and vegetable materials using extrusion processing.

2005-01-31

114

CT manifestations of ileal dysgenesis  

Energy Technology Data Exchange (ETDEWEB)

Ileal dysgenesis is an uncommon condition of unknown etiology occurring in the distal ileum in the region of the vitelline duct. The CT appearance of this lesion, although not previously described to our knowledge, is characteristic. We report a patient with ileal dysgenesis who had an abdominal CT scan to evaluate chronic iron deficiency anemia and protein-losing enteropathy. Recognition of this lesion by pediatric radiologists is important; so that surgical treatment, which is simple and effective, can be initiated quickly. (orig.)

2007-02-15

115

Arginine aminoacylation identity is context-dependent and ensured by alternate recognition sets in the anticodon loop of accepting tRNA transcripts.  

UK PubMed Central (United Kingdom)

Yeast arginyl-tRNA synthetase recognizes the non-modified wild-type transcripts derived from both yeast tRNA(Arg) and tRNA(Asp) with equal efficiency. It discriminates its cognate natural substrate,...Full Text Available

1996-09-16

116

An interface - marker technique applied to the study of metal silicide growth  

International Nuclear Information System (INIS)

An interface-marker technique has been used to investigate the relative rates of diffusion of Si and of metal atoms during the growth of metal silicide films. The technique enables recognition of a reference plane in thin film diffusion using Rutherford backscattering, while minimizing any perturbation of the diffusion process. Examples are drawn from studies of the growth of silicides of W, Mo, Ta, Nb, Pd and Pt. (orig.).

117

Adenine and guanine recognition of stop codon is mediated by different N domain conformations of translation termination factor eRF1  

UK PubMed Central (United Kingdom)

Positioning of release factor eRF1 toward adenines and the ribose-phosphate backbone of the UAAA stop signal in the ribosomal decoding site was studied using messenger RNA (mRNA) analogs containing...Full Text Available

2011-09-01

118

A statistical pattern recognition paradigm for structural health monitoring  

Energy Technology Data Exchange (ETDEWEB)

The process of implementing a damage detection strategy for aerospace, civil and mechanical engineering infrastructure is referred to as structural health monitoring (SHM). Here damage is defined as changes to the material and/or geometric properties of these systems, including changes to the boundary conditions and system connectivity, which adversely affect the system's current or future performance. Our approach is to address the SHM problem in the context of a statistical pattern recognition paradigm (Farrar, Nix and Doebling, 2001). In this paradigm, the process can be broken down into four parts: (1) Operational Evaluation, (2) Data Acquisition, (3) Feature Extraction, and (4) Statistical Model Development for Feature Discrimination. When one attempts to apply this paradigm to data from 'real-world' structures, it quickly becomes apparent that data cleansing, normalization, fusion and compression, which can be implemented with ...

2004-01-01

119

A single early life seizure impairs short-term memory but does not alter spatial learning, recognition memory, or anxiety  

UK PubMed Central (United Kingdom)

The impact of a single seizure on cognition remains controversial. We hypothesized that a single early life seizure (sELS) on rat post-natal day (P) 7 would alter only hippocampal-dependent...Full Text Available

2008-11-01

120

Numerical field calculations considering the human subject for engineering and safety assurance in MRI  

UK PubMed Central (United Kingdom)

Numerical calculations of static, switched, and radiofrequency (RF) electromagnetic (EM) fields considering the geometry and EM properties of the human body are used increasingly in MRI to explain...Full Text Available

2009-11-01

121

Numerical Weather Prediction Activities Report.  

Science.gov (United States)

This report presents a summary of highlights of the year 1978. It then discusses: Research and development in numerical analysis and prediction systems; Techniques, development and application of new products; Analysis-forecast systems in operation use du...

1978-01-01

122

Numerical Taxonomy of Some Bacteria Isolated from Antarctic and Tropical Seawaters1  

UK PubMed Central (United Kingdom)

Pfister, Robert M. (Lamont Geological Observatory, Palisades, N.Y.), and Paul R. Burkholder. Numerical taxonomy of some bacteria isolated from Antarctic and tropical seawaters. J....Full Text Available

1965-10-01

123

Measuring IBS patient reported outcomes with an abdominal pain numeric rating scale: results from the proof cohort  

UK PubMed Central (United Kingdom)

BackgroundControversy exists about how to effectively measure patient reported outcomes in IBS clinical trials. Pain numeric rating scales (NRS) are widely used in...Full Text Available

2009-12-01

124

Gonadal hormones modulate sex differences in judgments of relative numerousness in meadow voles, Microtus pennsylvanicus  

UK PubMed Central (United Kingdom)

Animals in a variety of taxa discriminate between a greater quantity and a lesser quantity of the same object, an ability that is referred to as relative numerousness judgment. For example,...Full Text Available

2009-01-01

125

Development of a Coke-Free Cupola Furnace. Energy Conserving Shaft Furnace for Iron Materials. Final Report.  

Science.gov (United States)

Coke-fired cupola furnaces were improved and made suitable for the production of high-quality casting melts by numerous additional devices. Moreover, they were equipped with environmental protection systems with numerous dust separation devices and afterb...

1986-01-01

126

Vortex-Excited Vibrations of Uniform Pivoted Cylinders in Uniform and Shear Flow  

Science.gov (United States)

The vortex-excited dynamics of a uniform pivoted cylinder in uniform and sheared flow was investigated experimentally. The experiments were numerically simulated using a diffusive Van der Pol oscillator model developed by Balasubramanian & Skop recently. Salient features of the experimental investigations and the numerical simulations are presented here. Comparisons between the experimentally recorded and numerically predicted structural response to vortex-excited vibrations, power spectral density measurements of near-wake velocity fluctuations and lock-in ranges are made. A comparison of the numerical predictions and the experimental data reveals good agreement.

2000-01-01

127

Numerical solutions for symmetric Bianchi type IX universes  

International Nuclear Information System (INIS)

(Aug 1973). United States Moser, AR Matzner, RA Ryan, MP Jr. Center

128

Numerical integration of the Feynman Path Integral for radiative transport  

International Nuclear Information System (INIS)

The radiative transport problem is cast in integral form using a transport kernel. The transport kernel has an explicit representation in terms of a Feynman Path Integral over all paths between selected points in a volume. This representation is setup in detail. Numerical evaluation of this Path Integral is formulated with a Frenet-Serret based procedure for generating valid random paths, and with a numerical evaluation of the weight for each valid path. Very early sanity checks of a numerical implementation are reported. Approaches to optimization are identified. (authors)

2009-05-03

129

Numerical Testbed for Laser Materials Processing  

Science.gov (United States)

... presented in this paper can be said to be truly three dimensional as opposed to other reported work that uses symmetric boundary conditions. ...

2002-01-24

130

Modeling Cavitation in Cryogenic Fluids: Validation for Liquid Nitrogen, Hydrogen, and Oxygen  

Science.gov (United States)

This viewgraph presentation provides an overview of research designed to provide a numerical

2003-01-01

133

Track clustering and vertexing algorithm for L1 trigger  

Energy Technology Data Exchange (ETDEWEB)

One of the keystones of the canceled BTeV experiment (proposed at Fermilab's Tevatron) was its sophisticated three-level trigger. The trigger was designed to reject 99.9% of light-quark background events and retain a large number of B decays. The BTeV Pixel Detector provided a 3-dimensional, high resolution tracking system to detect B signatures. The Level 1 pixel detector trigger was proposed as a two stage process, a track-segment finder and a vertex finder which analyzed every accelerator crossing. In simulations the track-segment finder stage outputs an average of 200 track-segments per accelerator crossing (2.5MHz). The vertexing stage finds vertices and associates track-segments with the vertices found. This paper proposes a novel adaptive pattern recognition model to find the number and the estimated location of vertices, and to cluster track-segments around those vertices. The track clustering and vertex finding is done in parallel. The pattern ...

2005-10-01

134

The mask detection technology for occluded face analysis in the surveillance system.  

Science.gov (United States)

The surveillance systems have been widely used in automatic teller machines (ATMs), banks, convenient stores, etc. For example, when a customer uses the ATM, the surveillance systems will record his/her face information. The information will help us understand and trace who withdrew money. However, when criminals use the ATM to withdraw illegal money, they usually block their faces with something (in Taiwan, criminals usually use safety helmets or masks to block their faces). That will degrade the purpose of the surveillance system. In previous work, we already proposed a technology for safety helmet detection. In this paper, we propose a mask detection technology based upon automatic face recognition methods. We use the Gabor filters to generate facial features and utilize geometric analysis algorithms for mask detection. The technology can give an early warning to save-guards when any "customer" or "intruder" blocks his/her face information with a mask. Besides, ...

2005-05-01

135

Automated Categorization Scheme for Digital Libraries in Distance Learning: A Pattern Recognition Approach  

Science.gov (United States)

Digital libraries play a crucial role in distance learning. Nowadays, they are one of the fundamental information sources for the students enrolled in this learning system. These libraries contain huge amount of instructional data (text, audio and video) offered by the distance learning program. Organization of the digital libraries is therefore very important for easy and fast access to the desired information. Improper categorization of data may mislead the students searching the library. Since manual categorization of huge amount of data might be challenging, an automatic and reliable method is needed. In this sense, this paper proposes an automated categorization scheme for digital libraries in distance learning. The categorization scheme is designed and developed by a pattern recognition approach. Effectiveness of the proposed scheme is evaluated on widely used Reuters database. The results of the experimental study verify that the proposed scheme is ...

2008-10-01

136

Affinity purification of sequence-specific DNA binding proteins.  

Science.gov (United States)

We describe a method for affinity purification of sequence-specific DNA binding proteins that is fast and effective. Complementary chemically synthesized oligodeoxynucleotides that contain a recognition site for a sequence-specific DNA binding protein are annealed and ligated to give oligomers. This DNA is then covalently coupled to Sepharose CL-2B with cyanogen bromide to yield the affinity resin. A partially purified protein fraction is combined with competitor DNA and subsequently passed through the DNA-Sepharose resin. The desired sequence-specific DNA binding protein is purified because it preferentially binds to the recognition sites in the affinity resin rather than to the nonspecific competitor DNA in solution. For example, a protein fraction that is enriched for transcription factor Sp1 can be further purified 500- to 1000-fold by two sequential affinity chromatography steps to give Sp1 of an estimated 90% homogeneity with 30% yield. ...

1986-08-01

137

One-dimensional numerical simulation of free-electron laser (FEL) amplifier with incorporate variable-parameter wiggler magnets  

International Nuclear Information System (INIS)

A physical model of free-electron laser (FEL) amplifier with variable-parameter wiggler magnets for one-dimensional numerical simulation is presented and a numerical example is given. The wiggler parameters, efficiency of energy conversion between electron beam and laser field, laser intensity, phase-space distributions and energy spectrum of electrons are computed. The period of synchronous oscillation and saturation value of laser intensity agree with estimated one.

138

Numerical methods for determining the inhomogeneity boundary in a boundary value problem for Laplace?s equation in a piecewise homogeneous medium  

British Library Electronic Table of Contents (United Kingdom)

A boundary value problem for Laplace?s equation in a bounded two-dimensional domain filled with a piecewise homogeneous medium is considered. The boundary of the inhomogeneity is assumed to be unknown. The inverse problem of determining the inhomogeneity boundary and the solution of the equation given the solution and its normal derivative on the boundary of the domain is discussed. Numerical methods are proposed for solving the inverse problem, and the results of numerical experiments are presented.

2011-01-01

139

Enhanced heat transfer through oscillatory flow  

Energy Technology Data Exchange (ETDEWEB)

The enhancement of longitudinal heat transfer by means of fluid pulsation in a pipe has been investigated analytically and numerically, including the transient state. The effects of pulsation amplitude, frequency, and pipe length on thermal properties such as effective thermal diffusivity and delay time are clarified. Their effects on numerical calculations are also presented and suggestions for efficient numerical calculations of this problem are made concerning the combination of parameters.

1994-03-01

140

A radiant temperature numerical method for laser-plasma diagnostic using SXRSC with absorption method  

International Nuclear Information System (INIS)

An numerical method was developed for measuring radiant temperature using a set of absorption-foils coupled to soft x ray streak camera, SXRSC, in laser plasma experiments. An numerical code, SCC, was given. An x-ray intensity ratio vs temperature was calculated for Parylene, C_3H_6, Mylar and Aluminium. A suitable range of the measuring temperature was discussed to some absorber.

1990-01-01

141

A numerical weather prediction model--Computational aspects on the CRAY-1  

Science.gov (United States)

This paper presents a case study in the design and implementation of a numerical weather prediction model on a supercomputer (CRAY-1). Following a historical introduction to the evolution of the model, the governing equations of the model are presented and the numerical solution of these forecast equations is described. A brief tutorial on the architecture of the CRAY-1 is presented with a discussion of how it affects the choice of algorithms and code design of the model. A summary of the advantages gained by use of the vector aspects of the CRAY-1 is included.

1984-01-01

142

A High-Wavenumber Viscosity for High-Resolution Numerical Methods  

Energy Technology Data Exchange (ETDEWEB)

Numerical simulations of compressible flows are commonly based on the Euler equations when effects of viscosity are thought to be negligible. These equations admit singular solutions, even in cases where the initial and boundary conditions are smooth. So-called ''Euler solvers'' rely on numerical dissipation, explicitly or implicitly present in the scheme, to regularize the problem, such that physical solutions are selected.

2003-02-19

143

Visualization of two-phase flow eddies in rectangular channels using real-time neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

Bubbly and slug flows have been analyzed using the afore-mentioned techniques. An image series of bubbly-slug flow is shown. The image separation time is 17 ms, and the total flow length is {approx} 10 cm. A circular eddy pattern that follows the slug can be readily seen and tracked, although reliability is low due to motion in the transverse direction. This motion also adds considerable error to the velocity measurements using image recognition technique. This will increase the reliability and accuracy of the tracking method.

1994-12-31

144

The Environmental Management Project Manager`s Handbook for improved project definition  

Energy Technology Data Exchange (ETDEWEB)

The United States Department of Energy (DOE) is committed to providing high quality products that satisfy customer needs and are the associated with this goal, DOE personnel must possess the knowledge, skills, and abilities to ensure successful job performance. In addition, there must be recognition that the greatest obstacle to proper project performance is inadequate project definition. Without strong project definition, DOE environmental management efforts are vulnerable to fragmented solutions, duplication of effort, and wastes resources. The primary means of ensuring environmental management projects meet cost and schedule milestones is through a structured and graded approach to project definition, which is the focus of this handbook.

1995-02-01

145

Search Efficiency in Indexing Structures for Similarity Searching  

CERN Document Server

Similarity searching finds application in a wide variety of domains including multilingual databases, computational biology, pattern recognition and text retrieval. Similarity is measured in terms of a distance function edit distance in general metric spaces, which is expensive to compute. Indexing techniques can be used reduce the number of distance computations. We present an analysis of various existing similarity indexing structures for the same. The performance obtained using the index structures studied was found to be unsatisfactory . We propose an indexing technique that combines the features of clustering with M tree(MTB) and the results indicate that this gives better performance.

2004-01-01

146

Position-sensitive spectroscopy of 252Cf fission fragments  

International Nuclear Information System (INIS)

The fission fragments from spontaneous fission of 252Cf have been measured with the spectrometric and position-sensitive semiconductor pixel detector Medipix2. Fragments are identified by pattern recognition of clusters generated in the Medipix2 pixel matrix sensor upon heavy particle hit. From analysis of cluster area, the distribution of kinetic energy of fission fragments is obtained. Together with a novel USB readout interface, the Medipix2/USB system operates as active nuclear emulsion in single-quantum and on-line tracking mode.

2007-05-11

147

NAME=\\  

Wastenet

...The RSPB: Birds by family: Owls E-mail to a friendE-newsletterContact us Home England Northern Ireland Scotland Wales About Overview Awards & recognition Contact ...Birds by family PrintHome Birds and wildlife Bird guide Birds by family Owls Owls Owls are specialised birds with round heads and rather flat ...or dished faces, with forward-facing eyes and a short, hooked bill. Most are nocturnal or crepuscular (active at dawn and dusk)... Owls are found all over the temperate and tropical parts of the world. Barn owl With heart shaped face, buff back ...

148

Mechanisms Underlying Visceral Hypersensitivity in Irritable Bowel Syndrome  

British Library Electronic Table of Contents (United Kingdom)

Visceral hypersensitivity is currently considered a key pathophysiological mechanism involved in pain perception in large subgroups of patients with functional gastrointestinal disorders, including irritable bowel syndrome (IBS). In IBS, visceral hypersensitivity has been described in 20%?90% of patients. The contribution of the central nervous system and psychological factors to visceral hypersensitivity in patients with IBS may be significant, although still debated. Peripheral factors have gained increasing attention following the recognition that infectious enteritis may trigger the development of persistent IBS symptoms, and the identification of mucosal immune, neural, endocrine, microbiological, and intestinal permeability abnormalities. Growing evidence suggests that these factors ...

2011-01-01

149

Machine Learning Techniques for Biometrics  

Science.gov (United States)

This chapter reports recent advances in the statistical learning literature that may be of interest for biometrics. In particular we discuss two different algorithmic settings, binary classification and multi-task learning, and analyze the two closely related problems of feature selection and feature learning. In the binary case the theoretical and algorithmic advances to feature selection are applied to solve face detection and face authentication problems. In the multi-task case we show how the data structure described by a group of features common to the various tasks can be effectively learned, and then we discuss how this approach could be used to address face recognition.

2009-01-01

150

Intermediate form of osteopetrosis with recessive inheritance  

International Nuclear Information System (INIS)

The clinical and radiographic features of the intermediate form of osteopetrosis in two sibs are presented in which the disorder appears to have been inherited as a recessive trait. Although this form of osteopetrosis has been poorly delineated, its recognition is practically important in order to give an accurate prognosis. This paper also presents an unusual complication of bilateral avascular necrosis of the femoral head in the younger sib. Radiographic changes of the femoral heads suggest those of Legg-Calve-Perthes disease, though the possibility of avascular necrosis following unrecognized femoral neck fracture is not completely excluded. (orig.).

151

Impingement fracture of the anteromedial tibial margin: a radiographic sign of combined posterolateral complex and posterior cruciate ligament disruption  

Energy Technology Data Exchange (ETDEWEB)

Marginal fractures of the tibial plateau are associated with a high incidence of soft tissue injuries to the stabilising structures of the knee joint. Injuries to the anterior cruciate ligament are associated with the Segond fracture and impingement fractures of the posteromedial tibial plateau. Recognition of these fractures aids diagnosis of these injuries. Marginal fractures of the tibial plateau associated with posterior cruciate ligament injuries are less common, though recently a ''reverse'' Segond fracture has been recognised. We describe a fracture of the anteromedial tibial plateau associated with complete disruption of the posterior cruciate ligament and posterolateral complex. (orig.)

2001-02-01

152

Immunity and tolerance to infections in experimental hematopoietic transplantation  

British Library Electronic Table of Contents (United Kingdom)

Resistance and tolerance are two types of host defense mechanisms that increase fitness in response to fungi. Several genetic polymorphisms in pattern recognition receptors, most remarkably Toll-like receptors (TLRs), have been described to influence resistance and tolerance to aspergillosis in distinct clinical settings. TLRs on dendritic cells pivotally contribute in determining the balance between immunopathology and protective immunity to the fungus. Epithelial cells also contribute to this balance via selected TLRs converging on indoleamine-2,3-dioxygenase (IDO). Studies in experimental hematopoietic transplantation confirmed the dichotomy of pathways leading to resistance and tolerance to the fungus providing new insights on the relative contribution of the hematopoietic/nonhematopoi...

2011-01-01

153

Imaging findings of abdominal peripheral primitive neuroectodermal tumor: report of four cases with pathological correlation  

British Library Electronic Table of Contents (United Kingdom)

Peripheral primitive neuroectodermal tumors (peripheral PNETs) are rare in the abdomen. We report the imaging findings of four peripheral PNETs arising in the abdomen. Three were ill-demarcated tumors and one was a well-demarcated tumor, with extensive local invasion and lymph node metastasis in two cases, respectively. The tumors are of inhomogeneous attenuation and heterogeneous enhancement after intravenous administration of contrast materials. Although their imaging manifestations cannot distinguish them from other sarcomas, recognition of these imaging features may be helpful in suggesting the possibility of peripheral PNETs in some cases.

2009-01-01

154

End user needs for enhanced IAEA Safeguards Information Management Capabilities  

International Nuclear Information System (INIS)

The International Atomic Energy Agency is undertaking a program for strengthening its safeguards on the recognition that safeguards must give assurance not only of the non-diversion of declared material or that declared facilities are not being misused, but also of the absence of any undeclared nuclear activities in States which have signed comprehensive safeguards agreements with the Agency. The IAEA has determined that the detection of undeclared nuclear activities and the creation of confidence in the continuing peaceful use of declared material and facilities is largely dependent on more information being made available to the Agency and on the capability of the Agency to make more effective use of this additional information, as well as existing information.

155

Dynamic programming and graph algorithms in computer vision.  

Science.gov (United States)

Optimization is a powerful paradigm for expressing and solving problems in a wide range of areas, and has been successfully applied to many vision problems. Discrete optimization techniques are especially interesting since, by carefully exploiting problem structure, they often provide nontrivial guarantees concerning solution quality. In this paper, we review dynamic programming and graph algorithms, and discuss representative examples of how these discrete optimization techniques have been applied to some classical vision problems. We focus on the low-level vision problem of stereo, the mid-level problem of interactive object segmentation, and the high-level problem of model-based recognition. PMID:20660950

2011-04-01

156

Avascular necrosis associated with nailing of femoral neck fracture  

Energy Technology Data Exchange (ETDEWEB)

Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. Sr/sup 85/-scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures.

1983-01-01

157

Avascular necrosis associated with nailing of femoral neck fracture  

International Nuclear Information System (INIS)

Two patients with femoral neck fractures, one displaced and one undisplaced, are presented. Preoperative intravital staining with tetracycline and Tc-MDP scintimetry both showed intact femoral head circulation while Tc-MDP-scintimetry 1 week after operation showed pronounced circulatory deficiency. SR"8"5-scintimetry performed at the same time was inconclusive. Segmental collapse was observed radiographically, 8 and 12 months postoperatively. The major vascular injury resulting in avascularity most probably occured during the procedure of osteosynthesis, and Tc-MDP-scintimetry was found suitable for early postoperative recognition of avascular necrosis in both fractures. (author).

158

Analysis of the tet repressor-operator interactions using the uracil-DNA glycosylase footprinting system  

Energy Technology Data Exchange (ETDEWEB)

The tet repressor regulated expression of the Tn-10-encoded tetracycline resistance determinant in a tetracycline-dependent manner. In the absence of tetracycline, the tet repressor binds as a dimer to the 19-base-pair palindromic tet operator sequence. Amino acid homologies and genetic studies with trans-dominant mutants suggest that sequence-specific recognition of the tet operator involves the extensively studied helix-turn-helix motif. We have used the uracil-DNA glycosylase (UDG) footprinting systems to identify thymine contacts in the tet operator that are essential for the formation of tet repressor-operator complexes.

1994-12-31

159

Ranking Hearing Aid Input-Output Functions for Understanding Low-, Conversational-, and High-Level Speech in Multitalker Babble  

Science.gov (United States)

Purpose: To determine the rankings of 6 input-output functions for understanding low-level, conversational, and high-level speech in multitalker babble without manipulating volume control for listeners with normal hearing, flat sensorineural hearing loss, and mildly sloping sensorineural hearing loss. Method: Peak clipping, compression limiting, and 4 wide dynamic range compression (WDRC) input-output functions were compared in a repeated-measure design. Interactions among the compression characteristics were minimized. Speech and babble were processed and recorded at 3 input levels: 45, 65, and 90 dB sound pressure level. Speech recognition of 3 groups of listeners (n = 6/group) was tested for speech processed by each input-output function and at each input level. Results: Input-output functions that made low-level speech audible and high-level speech less distorted by avoiding peak clipping or severe compression yielded higher speech ...

2007-04-01

160

RangerMaster{trademark}: Real-time pattern recognition software for in-field analysis of radiation sources  

Energy Technology Data Exchange (ETDEWEB)

RangerMaster{trademark} is the embedded firmware for Quantrad Sensor`s integrated nuclear instrument package, the Ranger{trademark}. The Ranger{trademark}, which is both a gamma-ray and neutron detection system, was originally developed at Los Alamos National Laboratory for in situ surveys at the Plutonium Facility to confirm the presence of nuclear materials. The new RangerMaster{trademark} software expands the library of isotopes and simplifies the operation of the instrument by providing an easy mode suitable for untrained operators. The expanded library of the Ranger{trademark} now includes medical isotopes {sup 99}Tc, {sup 201}Tl, {sup 111}In, {sup 67}Ga, {sup 133}Xe, {sup 103}Pa, and {sup 131}I; industrial isotopes {sup 241}Am, {sup 57}Co, {sup 133}Ba, {sup 137}Cs, {sup 40}K, {sup 60}Co, {sup 232}Th, {sup 226}Ra, and {sup 207}Bi; and nuclear materials {sup 235}U, {sup 238}U, {sup 233}U, and {sup 239}Pu. To accomplish isotopic identification, a simulated spectrum for each of the ...

1998-12-31

161

Shock stand-off distance of a solid sphere decelerating in transonic velocity range  

British Library Electronic Table of Contents (United Kingdom)

The shock stand-off distance of a spherical model flying with transonic speeds is determined through numerical simulations. The model decelerates due to drag forces caused by the pressure and viscous shear stress at the model surface. Two-dimensional axisymmetric numerical codes with numerical grids fixed to the flying spherical model are used in the simulations. Numerically determined shock stand-off distances are compared with experimental data obtained in a previous study as well as with those obtained in our ballistic-range experiments. The numerical results and the experimental data are found to be in good agreement. In addition, the time-dependent shock stand-off distance of a decelerating model is investigated.

2011-01-01

162

Mapping Equivalence for Symbolic Sequences: Theory and Applications  

CERN Document Server

Processing of symbolic sequences represented by mapping of symbolic data into numerical signals is commonly used in various applications. It is a particularly popular approach in genomic and proteomic sequence analysis. Numerous mappings of symbolic sequences have been proposed for various applications. It is unclear however whether the processing of symbolic data provides an artifact of the numerical mapping or is an inherent property of the symbolic data. This issue has been long ignored in the engineering and scientific literature. It is possible that many of the results obtained in symbolic signal processing could be a byproduct of the mapping and might not shed any light on the underlying properties embedded in the data. Moreover, in many applications, conflicting conclusions may arise due to the choice of the mapping used for numerical representation of symbolic data. In this paper, we present a ...

2009-01-01

163

Prediction of motions and tension in mooring lines on slack-moored floating oceanic architectural building in coastal zones  

Energy Technology Data Exchange (ETDEWEB)

The present paper is concerned with the prediction method for the motions and tensions of mooring lines on slack-moored floating oceanic architectural building in coastal zone. The motions and the tensions of mooring lines were estimated by the time domain numerical simulation in the present method. The present method includes the nonlinearity of mooring system, slow varying wave drift force. The authors performed a time domain numerical simulation for motions and the tensions of mooring lines on floating barge in two component waves. Also, the results obtained by numerical simulation were compared with the experimental results. The validity of the present method was confirmed.

1995-12-31

164

Modelling of Aquitaine II pipe whipping test with the EUROPLEXUS fast dynamics code  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a numerical simulation with the EUROPLEXUS fast dynamics software of a pipe whipping phenomenon occurring in the thermal hydraulic conditions of a loss of coolant accident in a PWR primary circuit. Different physical phenomena take place simultaneously during the rupture and the whipping of the pipe such as plasticity, contact, large displacements, two-phase flow regime and fluid structure interaction. Two kinds of numerical models - a simplified pipeline model and a mixed 1D/3D model - are considered and compared throughout modelling and computation. Numerical results are compared with experimental data belonging to the Aquitaine II test campaign.

2005-08-01

165

Consistent Higher-Order Corrections to Stop_i -> Sbottom_j H^+ in the Complex MSSM  

CERN Document Server

We review an analysis of a consistent renormalization of the top and bottom quark/squark sector of the MSSM with complex parameters (cMSSM). Various renormalization schemes are defined, analyzed analytically and tested numerically in the decays Stop_2 -> Sbottom_i H^+/W^+ (i = 1,2). No scheme is found that produces numerically acceptable results over all the cMSSM parameter space, where problems occur mostly already for real parameters. Some numerical examples for Gamma(Stop_2 -> Sbottom_1 H^+) in our preferred scheme, "m_b, A_b DRbar" are shown.

2010-01-01

166

To Possibility of Usage of FMW Plasma Heating Scenarios in the ICR Frequency Range in the Torsatron Reactor  

International Nuclear Information System (INIS)

The problem of fast wave plasma heating in reactor-torsatron at the ICRF range in scenarios, optimal for fusion reactor, is numerically studied.

2006-01-01

167

Safety calculation for an underground repository for radioactive waste: the first objective of the alliances calculation software platform  

International Nuclear Information System (INIS)

The aim of the safety calculation is to quantify through numerical modelling the radiological impact (molar flow, human dose) of a potential repository for radioactive waste on the Meuse/Haute Marne site at Bure. A selection process is underway for safety scenarios and their phenomenological and numerical conceptual models upstream from the safety calculation. This involves defining and quantifying the geometric and dimensional representations of the repository for each scenario plus the physical, mathematical and numerical models that reflect its behaviour and the uncertainties associated with all the parameters required to quantify the impact. A summary will be given of these various aspects. The numerical simulations are then performed on the Alliances platform which integrates the various computer codes required for the physical representation of the system. (authors)

2005-03-14

168

Relationship of Optical Coating on Thermal Radiation ...  

Science.gov (United States)

drical Enclosures Using a Numerical Ray Tracing Technique. NASA. TM-I02527, 1990 . Buckley, H.: Radiation from the Interior of a Reflecting Cylinder. Philos. ...

169

Ras activation of genes: Mob-1 as a model.  

UK PubMed Central (United Kingdom)

The ras oncogenes function by indirectly controlling expression of a subset of yet-undefined genes that are crucial for cell growth and differentiation. In a differential display strategy, numerous...Full Text Available

1994-12-20

170

Publications of Los Alamos research 1988  

Energy Technology Data Exchange (ETDEWEB)

This bibliography lists unclassified publications of work done at the Los Alamos National Laboratory for 1988. The entries, which are subdivided by broad subject categories, are cross-referenced with an author index and a numeric index.

1989-12-01

171

Planet Forming Protostellar Disks - NASA Technical Report Server ...  

Science.gov (United States)

terms of 11) numerical models, 2D SPH simulations, and analytic models. The 1D model was useful for determining the evolution over very long timescales. ...

172

Numerical weather prediction for fire hazards on Oahu/Hawaii  

Science.gov (United States)

Brush fires, especially during the summer months, are hazards that occasionally threaten the leeward (Waianae) coast of Oahu in Hawaii. The prediction of future ... ...

173

Numerical simulation of shallow-water dam break flows in open channels using smoothed particle hydrodynamics  

British Library Electronic Table of Contents (United Kingdom)

SummaryA meshless numerical model is proposed to investigate shallow-water dam break flows in 1D open channels. The numerical model is to solve the shallow water equations (SWE) based on smoothed particle hydrodynamics (SPH). The concept of slice water particles (SWP) is adopted in the SPH-SWE formulation. The numerical sensitivity analysis is first performed to study the appropriate SWP number and variable smoothing length through dam break flows in an idealized 1D channel with dry/wet beds. Extensive validation by comparison with laboratory and field data is next conducted for four benchmark problems, including dam break flows through a rough flat channel, a rough bumpy channel with various downstream boundary conditions, a nonprismatic channel, and a realistic scale model of the Toce ri...

2011-01-01

175

Numerical analysis of melting/solidification phenomena using a moving boundary problem analysis method X-FEM  

International Nuclear Information System (INIS)

A numerical analysis method for melting/solidification phenomena has been developed to evaluate a feasibility of several candidate techniques in the nuclear fuel cycle. Our method is based on the eXtended Finite Element Method (X-FEM) which has been used for moving boundary problems. Key technique of the X-FEM is to incorporate signed distance function into finite element interpolation to represent a discontinuous gradient of the temperature at a moving solid-liquid interface. Construction of the finite element equation, the technique of quadrature and the method to solve the equation are reported here. The numerical solutions of the one-dimensional Stefan problem, solidification in a two-dimensional square corner and melting of pure gallium are compared to the exact solutions or to the experimental data. Through these analyses, validity of the newly developed numerical analysis method has been demonstrated. (author)

2008-06-01

176

Numerical Simulation of Quarry Source and Reflection ...  

Science.gov (United States)

... that range from relatively low frequency strong ground motion modeling [Vidale et al., 1985] to high frequency reverse time migration of seismic ...

1990-08-01

177

Numerical Simulation of Cirrus Clouds - Fire Case Study and ...  

Science.gov (United States)

... being pulled out of water, the movement is restricted ... This heating depended on the particle size ... hydrometeor injection into the upper tropopause. ...

1991-08-12

178

Numerical Modelling of Vortex Flow Instabilities and ...  

Science.gov (United States)

... Fig.9 Hurricane Fran, Sept.4, 1996, (NOAA / NASA) Fig.10 Whirlpool Galaxy (M 51/NGC 5194), C. Messier (1773) / P. Mechain (1781) ...

2003-03-01

180

NASAPerformance Report - NASA Technical Reports Server  

Science.gov (United States)

test bed (ADTT) tools technology. Glenn. Research. Center: Aircraft icing training video for regional and cor- porate pilots. Numerical propulsion ...

181

Mitochondrial uncoupling and lifespan  

UK PubMed Central (United Kingdom)

The quest to understand why we age has given rise to numerous lines of investigation that have gradually converged to include metabolic control by mitochondrial activity as a major player. That...Full Text Available

2010-01-01

182

Kim IL Sung (North Korea), Another Saddam Hussein (Iraq)? ...  

Science.gov (United States)

... 10 Page 16. 1987, and (3) numerous infiltration excursions including attempted sabotage of the Wolsung nuclear plant in 1987. Kim Ii ...

1992-02-13

183

Is Phenacetin a Nephrotoxin?  

UK PubMed Central (United Kingdom)

Numerous reports of chronic renal disease in patients who habitually use phenacetin-containing compounds to excess have aroused considerable controversy over the possible relationship between phenacetin,...Full Text Available

1964-08-01

184

Ionospheric Modeling and Propagation Analysis.  

Science.gov (United States)

... these features and yields results which are two orders of magnitude faster than those available using conventional numerical ray tracing techniques ...

1980-04-01

185

GOES-R GLM Instrument Page  

Science.gov (United States)

ground strike hazards 3) Advancements in the initialization of numerical weather prediction models through better identification of deep convection 4) Improved routing of...

2011-08-27

186

Dynamics of multicomponent vesicles in a viscous fluid  

UK PubMed Central (United Kingdom)

We develop and investigate numerically a thermodynamically consistent model of two-dimensional multicomponent vesicles in an incompressible viscous fluid. The model is derived using an energy...Full Text Available

2010-01-01

187

Degradation of malathion by salt-marsh microorganisms.  

UK PubMed Central (United Kingdom)

Numerous bacteria from a salt-marsh environment are capable of degrading malathion, an organophosphate insecticide, when supplied with additional nutrients as energy and carbon sources. Seven isolates...Full Text Available

1977-02-01

188

Deforestation: Much Ado about the Contribution to ... - Blogs - NASA  

Science.gov (United States)

Jan 7, 2010 ... Deforestation. The environmental implications of the word are as numerous as the syllables. And scientists like Jim Collatz have the job of ...

189

DIVISION OF - NASA Technical Reports Server  

Science.gov (United States)

(Lactuca scariole),morning glory (Ipomea sp.), broomsedge (Andropogon virginicus ) and numerous composites. Because this area is leveed -and managed it ...

190

Calculation of model neutron stars with pion condensation  

Energy Technology Data Exchange (ETDEWEB)

It is shown numerically that on a time scale of order 1 msec a neutron star with pion condensation will undergo separation into a core and an envelope with a sharp interface. The envelope will not, however, be ejected.

1982-01-01

191

Buffet Active Control - Experimental and Numerical Results  

Science.gov (United States)

... high- lift separated compressible flows over airfoils ... Proceedings AGARD-CP- 515, paper 26, Symposium ... Viscous-inviscid flow matching Analysis of ...

2001-06-01

192

Analysis of Mammalian Carboxylesterase Inhibition by Trifluoromethylketone-Containing Compounds  

UK PubMed Central (United Kingdom)

Carboxylesterases (CE) are ubiquitous enzymes that hydrolyze numerous ester-containing xenobiotics, including complex molecules, such as the anticancer drugs irinotecan (CPT-11) and capecitabine...Full Text Available

2007-03-01

193

-!23(!,, - The Marshall Star - NASA  

Science.gov (United States)

Dec 6, 2007 ... provided cleaning services to numerous Marshall facilities over .... Two Schwinn Missle FS battery-powered scooters, $75. 683-4758 ...

194

Petrophysical Analysis and Geographic Information System for San Juan Basin Tight Gas Reservoirs  

Energy Technology Data Exchange (ETDEWEB)

The primary goal of this project is to increase the availability and ease of access to critical data on the Mesaverde and Dakota tight gas reservoirs of the San Juan Basin. Secondary goals include tuning well log interpretations through integration of core, water chemistry and production analysis data to help identify bypassed pay zones; increased knowledge of permeability ratios and how they affect well drainage and thus infill drilling plans; improved time-depth correlations through regional mapping of sonic logs; and improved understanding of the variability of formation waters within the basin through spatial analysis of water chemistry data. The project will collect, integrate, and analyze a variety of petrophysical and well data concerning the Mesaverde and Dakota reservoirs of the San Juan Basin, with particular emphasis on data available in the areas defined as tight gas areas for purpose of FERC. A relational, geo-referenced database (a geographic information system, or GIS) ...

2008-10-01

195

Using Genetic Algorithms for Texts Classification Problems  

CERN Document Server

The avalanche quantity of the information developed by mankind has led to concept of automation of knowledge extraction - Data Mining ([1]). This direction is connected with a wide spectrum of problems - from recognition of the fuzzy set to creation of search machines. Important component of Data Mining is processing of the text information. Such problems lean on concept of classification and clustering ([2]). Classification consists in definition of an accessory of some element (text) to one of in advance created classes. Clustering means splitting a set of elements (texts) on clusters which quantity are defined by localization of elements of the given set in vicinities of these some natural centers of these clusters. Realization of a problem of classification initially should lean on the given postulates, basic of which - the aprioristic information on primary set of texts and a measure of affinity of elements and classes.

2009-01-01

196

Use of a tethersonde measurement system to conduct a Doppler SODAR performance audit  

Energy Technology Data Exchange (ETDEWEB)

With the increased usage of dispersion models that require stack top wind information, such as the Complex Terrain Dispersion Model (CTDM), the need for a reliable method to collect elevated wind data has also increased. Doppler Sound Detection and Ranging (SODAR) instruments have gained recognition as a viable means of collecting such data. SODAR technology has improved greatly over the last decade and is now a cost effective alternative to tall meteorological towers. SODARs are remote sensing devices that sample the atmosphere and calculate wind speed and wind direction data at different altitudes. This is accomplished by measuring the doppler shift of an acoustic pulse emitted by a ground level antenna.

1994-12-31

197

Universal Similarity  

CERN Document Server

We survey a new area of parameter-free similarity distance measures useful in data-mining, pattern recognition, learning and automatic semantics extraction. Given a family of distances on a set of objects, a distance is universal up to a certain precision for that family if it minorizes every distance in the family between every two objects in the set, up to the stated precision (we do not require the universal distance to be an element of the family). We consider similarity distances for two types of objects: literal objects that as such contain all of their meaning, like genomes or books, and names for objects. meaning, like genomes or books, and names for objects. The latter may have literal embodyments like the first type, but may also be abstract like ``red'' or ``christianity.'' For the first type we consider a family of computable distance measures corresponding to parameters expressing similarity according to particular features between pairs of literal ...

2005-01-01

198

Transient suppression of MLH1 allows effective single-nucleotide substitution by single-stranded DNA oligonucleotides  

British Library Electronic Table of Contents (United Kingdom)

Short synthetic single-stranded oligodeoxyribonucleotides (ssODNs) can be used to introduce subtle modifications into the genome of mouse embryonic stem cells (ESCs). We have previously shown that effective application of ssODN-mediated gene targeting in ESC requires (transient) suppression of DNA mismatch repair (MMR). However, whereas transient down-regulation of the mismatch recognition protein MSH2 allowed substitution of 3 or 4 nucleotides, 1 or 2 nucleotide substitutions were still suppressed. We now demonstrate that single- or dinucleotide substitution can effectively be achieved by transient down-regulation of the downstream MMR protein MLH1. By exploiting highly specific real-time PCR, we demonstrate the feasibility of substituting a single basepair in a non-selectable gene. Howev...

2011-01-01

199

Supporting Children-s Social and Emotional Well-being: Does -Having a Say- Matter?  

British Library Electronic Table of Contents (United Kingdom)

This article argues the importance of ensuring initiatives aimed at improving children-s social and emotional well-being are based on sound participatory principles. The discussion posits links between the recognition of children, dialogic approaches to participation, changing conceptualisations of children and childhood, and children-s well-being. It explores these links in light of one particular initiative, Seasons for Growth (Graham, 1996, 2002, Seasons for Growth; Loss and Grief Education Program. MacKillop Foundation), an education programme built around emerging evidence that giving children a voice assists them to adapt to family change. The paper concludes with insights into what is involved when we locate notions of -having a say- as a key element in promoting children-s well-bei...

2011-01-01

200

Studies on the diagnostic accuracy of lymphography  

International Nuclear Information System (INIS)

Contradictory reports in the literature on the reliability of lymphography stimulated the authors to test the diagnostic accuracy, employing methods which are approximately analogous to practice, using carcinoma of the cervix as the model on which the study was carried out. Using 21 observers it was found that there was no correlation between their experience and on-target accuracy of the diagnosis. Good observers obtained an accuracy of 85% with good proportions between sensitivity in the recognition of detail, specificity and readiness to arrive at a decision on the basis of discriminatory ability. With the help of the concept of the ROC curves, the position taken up by the observers in respect of diagnostic decisions, and a complex manner of assessing the various characteristic factors determining diagnostic accuracy, are demonstrated. This form of test, which permits manipulation of different variants of diagnosis, is recommended, among other things, for ...

201

Stress corrosion cracking: 1965-1990  

Energy Technology Data Exchange (ETDEWEB)

Advances in the theory and practice of stress corrosion cracking (SCC) are reviewed for the period 1965-1990. The proceedings of two landmark conferences are used as a basis for discussion: Ohio State University (1967) and Kohler, WI (1988). The discussion is developed around the following topics: metal-environment combinations, testing, fractography, metallurgical aspects, electrochemical aspects and crack chemistry, mechanisms, and prediction and mitigation. It is concluded that the main developments since 1967 are the recognition of the lack of specificity of SCC environments, the use of slow strain rate and fracture mechanics testing, quantitative SEM fractography, studies of grain boundary structure and compositions, transient electrochemistry of bare metal surfaces, measurement and modelling of crack chemistry, elaboration of several SCC models, including slip-dissolution and film induced cleavage, and mitigation by alloy development or anodic protection. ...

1990-01-01

202

Sialography, echography and computed tomography in parotid gland study  

International Nuclear Information System (INIS)

The diagnostic accuracy of sialography and ultrasonography (US) in the evaluation of parotid masses is evaluated. Furthermore the role of computed tomography (CT) in this pathology is discussed. In the personal experience US proved to be the best method in the recognition of a parotid tumor while sialography was superior in defining the intra or extraparotid site. The two investigations showed the same accuracy in the definition of benign or malignant nature of the mass. Therefore we consider US the only investigation in most istances; sialography could be performed when the site of the lesion is uncertain or an inflammatory lesion is suspected. CT is never the first investigation; its use is limited to a low number of cases, mainly for the evaluation of large masses and when the association US-sialography does not allow a sure diagnosis.

1985-01-01

203

Role of FFTF in assessing structural feedbacks and inherent safety of LMR's  

International Nuclear Information System (INIS)

The possibility of developing reactor designs with inherent safety characteristics sufficient to provide walk away safety is receiving additional emphasis in the LMR program. A key element in this effort is the recognition that LMR's possess safety characteristics above and beyond those employed in past safety review processes. Some of these additional safety characteristics are due to reactivity feedback effects caused by small structural movements during hypothetical severe design transients. The effects of these characteristics upon the behavior of the FFTF under such transients has been assessed and is discussed in this paper. The paper also presents a preliminary test matrix which might allow experimental verification of the structural reactivity feedback effects. Such experimental verification should be very useful to innovative designers seeking to optimize inherent safety.

1985-07-01

204

Role of FFTF in assessing structural feedbacks and inherent safety of LMR's  

International Nuclear Information System (INIS)

The possibility of developing reactor designs with inherent safety characteristics sufficient to provide ''walk away'' safety is receiving additional emphasis in the LMR program. A key element in this effort is the recognition that LMR's possess safety characteristics above and beyond those employed in past safety review processes. Some of these additional safety characteristics are due to reactivity feedback effects caused by small structural movements during hypothetical severe design transients. The effect of these characteristics upon the behavior of the FFTF under such transients has been assessed and is discussed in this paper. The paper also presents a preliminary test matrix which might allow experimental verification of the structural reactivity feedback effects. Such experimental verification should be very useful to innovative designers seeking to optimize inherent safety. 8 refs., 1 fig., 2 tabs.

1985-04-21

205

Recursive neural networks for processing graphs with labelled edges: theory and applications.  

Science.gov (United States)

In this paper, we introduce a new recursive neural network model able to process directed acyclic graphs with labelled edges. The model uses a state transition function which considers the edge labels and is independent both from the number and the order of the children of each node. The computational capabilities of the new recursive architecture are assessed. Moreover, in order to test the proposed architecture on a practical challenging application, the problem of object detection in images is also addressed. In fact, the localization of target objects is a preliminary step in any recognition system. The proposed technique is general and can be applied in different detection systems, since it does not exploit any a priori knowledge on the particular problem. Some experiments on face detection, carried out on scenes acquired by an indoor camera, are reported, showing very promising results. PMID:16181770

2005-09-21

206

Policy of air protection in Poland  

International Nuclear Information System (INIS)

The changed political situation and recognition of the acute destruction of the natural environment in Poland have caused a series of actions aimed at preventing further deterioration of Polish environment. One of the most important events which took place in the last few years was the enactment by the Polish Parliament in May 1991 of the Act on the National Ecological Policy. The basic assumption of the new environmental policy is a declaration that sustainable development will in future direct economic development in Poland. The aim of the presented paper is to introduce existing policy of air protection and instruments which have been implemented to protect the air. Special attention is paid to legislation instruments, introduction and enforcement of proper economic mechanisms strengthening air protection and foreign policy aiming at increasing foreign assistance for this objective. Pollutants involved include sulfur dioxide, nitrogen oxides, carbon dioxide and ...

1995-06-26

207

On Bregman Distances and Divergences of Probability Measures  

CERN Document Server

The paper introduces scaled Bregman distances of probability distributions which admit non-uniform contributions of observed events. They are introduced in a general form covering not only the distances of discrete and continuous stochastic observations, but also the distances of random processes and signals. It is shown that the scaled Bregman distances extend not only the classical ones studied in the previous literature, but also the information divergence and the related wider class of convex divergences of probability measures. An information processing theorem is established too, but only in the sense of invariance w.r.t. statistically sufficient transformations and not in the sense of universal monotonicity. Pathological situations where coding can increase the classical Bregman distance are illustrated by a concrete example. In addition to the classical areas of application of the Bregman distances and convex divergences such as recognition, classification, ...

2009-01-01

208

NRC safety research in support of regulation, FY 1992. Volume 7  

Energy Technology Data Exchange (ETDEWEB)

This report, the eighth in a series of annual reports, was prepared in response to congressional inquiries concerning how nuclear regulatory research is used. It summarizes the accomplishments of the Office of Nuclear Regulatory Research during FY 1992. A special emphasis on accomplishments in nuclear power plant aging research reflects recognition that a number of plants are entering the final portion of their original 40-year operating licenses and that, in addition to current aging effects, a focus on safety considerations for license renewal becomes timely. The primary purpose of performing regulatory research is to develop and provide the Commission and its staff with the technical bases for regulatory decisions on the safe operation of licensed nuclear reactors and facilities, to find unknown or unexpected safety problems, and to develop data and related information for the purpose of revising the Commission`s rules, regulatory guides, or other guidance.

1993-05-01

209

NRC safety research in support of regulation, FY 1992  

Energy Technology Data Exchange (ETDEWEB)

This report, the eighth in a series of annual reports, was prepared in response to congressional inquiries concerning how nuclear regulatory research is used. It summarizes the accomplishments of the Office of Nuclear Regulatory Research during FY 1992. A special emphasis on accomplishments in nuclear power plant aging research reflects recognition that a number of plants are entering the final portion of their original 40-year operating licenses and that, in addition to current aging effects, a focus on safety considerations for license renewal becomes timely. The primary purpose of performing regulatory research is to develop and provide the Commission and its staff with the technical bases for regulatory decisions on the safe operation of licensed nuclear reactors and facilities, to find unknown or unexpected safety problems, and to develop data and related information for the purpose of revising the Commission's rules, regulatory guides, or other ...

1993-05-01

210

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Wastenet

...the School, the research group structure was recently revised and now comprises the following teams: Drug Design and Analysis Pharmaceutics Pharmacy Practice and Policy Pharmacological and Biomedical Science The current structure was designed to take into account the future development of research in the academic area. The ...Discovery, Molecular Modelling, Pharmacology and Molecular Biology) and international recognition (Biological Sciences), which have now been re-organised into the Drug Design and Analysis and Pharmacological and Biomedical Sciences teams. The reorganisation also aimed to improve the research reputation of the other teams. The improvements in ... Email to a friend Print Within this area Drug design and analysis Pharmaceutics Pharmacy practice and policy Pharmacological and biomedical sciences Projects Publications Staff Considering a course? Research Degrees Course Finder Order a Prospectus Subject Areas Sunderland Facts Student Life Getting ...

211

NAME=\\  

Wastenet

...The RSPB: Great crested grebe A delightfully elegant waterbird with ornate head plumes which led to its being hunted for its feathers, almost leading to its extermination from the UK. E-mail to a friendE-newsletterContact us Home England Northern Ireland Scotland Wales About Overview Awards & recognition Contact us Facts and figures History How we are run Inspiring work Job vacancies Looking to the future Media centre Offices The RSPB view ...status: Green Listen Get Flash player Play sound 1 videoLatin name Podiceps cristatusFamily Grebes (Podicipedidae)Overview A delightfully elegant waterbird with ornate head plumes which led to its being hunted for its feathers, almost leading to its extermination from the UK. They dive to feed and also to escape, preferring this to flying. On land they are clumsy because their feet are placed so far back on their bodies. ...

212

Monolayers at air-water interfaces: from origins-of-life to nanotechnology  

British Library Electronic Table of Contents (United Kingdom)

Abstract The air-water interface presents several interesting features, namely a) a molecularly flat environment, b) a boundary region between two phases with different dielectric constants, c) permits or promotes dynamic interactions within the interface region, and d) a point of interaction between hydrophobic compounds and aqueous molecules. Accordingly, Langmuir monolayers at the air-water interface have several unique characteristics and properties, which require investigation. In this review-type personal account, typical examples of molecular recognition and molecular patterning at air-water interfaces are first introduced, followed by descriptions of specific and unusual properties of monolayers on water. In addition, two examples of our own results concerning Langmuir monolayers a...

2011-01-01

213

Metallointercalators and Metalloinsertors  

Science.gov (United States)

Since the elucidation of the structure of double helical DNA, the construction of small molecules that recognize and react at specific DNA sites has been an area of considerable interest. In particular, the study of transition metal complexes that bind DNA with specificity has been a burgeoning field. This growth has been due in large part to the useful properties of metal complexes, which possess a wide array of photophysical properties and allow for the modular assembly of an ensemble of recognition elements. Here we review recent experiments in our laboratory aimed at the design and study of octahedral metal complexes that bind DNA non-covalently and target reactions to specific sites. Emphasis is placed both on the variety of methods employed to confer site-specificity and upon the many applications for these complexes. Particular attention is given to the family of complexes recently designed that target single base mismatches in duplex DNA through ...

2007-09-20

214

Metallo-intercalators and metallo-insertors.  

Science.gov (United States)

Since the elucidation of the structure of double helical DNA, the construction of small molecules that recognize and react at specific DNA sites has been an area of considerable interest. In particular, the study of transition metal complexes that bind DNA with specificity has been a burgeoning field. This growth has been due in large part to the useful properties of metal complexes, which possess a wide array of photophysical attributes and allow for the modular assembly of an ensemble of recognition elements. Here we review recent experiments in our laboratory aimed at the design and study of octahedral metal complexes that bind DNA non-covalently and target reactions to specific sites. Emphasis is placed both on the variety of methods employed to confer site-specificity and upon the many applications for these complexes. Particular attention is given to the family of complexes recently designed that target single base mismatches in duplex DNA through ...

2007-09-20

215

Laparoscopic examination of the reproductive organs in women treated for infertility; Laparoskopowa ocena narzadow plciowych u kobiet leczonych z powodu nieplodnosci  

Energy Technology Data Exchange (ETDEWEB)

The authors discuss 84 cases of laparoscopic examination of women with primary or secondary infertility. The patients qualified for this examination had undergone at least 26 weeks of conventional treatment with no effect. In 7 cases the reproductive organ was found to be in order, with fallopian tubes fully patent. In 43 cases tubar inpatency was found (using hysterosalpingographic examination). The remaining patients suffered from other reproductive organ disorders. Therefore, the laparoscopic examination made detailed recognition of the causes of infertility possible and thus helped to establish the proper treatment. Additionally, in some cases it enabled the immediate removal of the source of infertility. (author)

1993-12-31

216

Isolation of functional mitochondria from rat kidney and skeletal muscle without manual homogenization  

British Library Electronic Table of Contents (United Kingdom)

Isolation of functional and intact mitochondria from solid tissue is crucial for studies that focus on the elucidation of normal mitochondrial physiology and/or mitochondrial dysfunction in conditions such as aging, diabetes, and cancer. There is growing recognition of the importance of mitochondria both as targets for drug development and as off-target mediators of drug side effects. Unfortunately, mitochondrial isolation from tissue is generally carried out using homogenizer-based methods that require extensive operator experience to obtain reproducible high-quality preparations. These methods limit dissemination, impede scale-up, and contribute to difficulties in reproducing experimental results over time and across laboratories. Here we describe semiautomated methods to disrupt tissue ...

2011-01-01

217

Investigation of the sample characteristics needed for the determination of the origin of uranium-bearing materials  

International Nuclear Information System (INIS)

A set of 35 uranium ore and 10 yellow cake samples, collected worldwide from different mines and production sites, were analyzed for their impurity spectrum by ICP-MS. Pattern recognition techniques such as cluster analysis were applied to the data set in order to characterize samples with relation to their geographical origin. The results obtained show a clear relationship between samples taken from the same geological origin and constitute a satisfactory fingerprint for establishing the origin of the material. In addition to the impurity data, data on the isotopic composition of radiogenic lead is used to resolve ambiguity when impurity cluster analysis fails to deliver unambiguous origin data. (author)

2008-10-01

218

Incorporating Traditional Knowledge in an International Regime on Access to Genetic Resources and Benefit Sharing: Problems and Prospects  

British Library Electronic Table of Contents (United Kingdom)

The Seventh Meeting of the Conference of the Parties (2004) of the Convention on Biological Diversity established a mandate for the negotiation of an international regime on Access to Genetic Resources and Benefit Sharing arising from their utilization. Negotiations have been proceeding and have entered the final phase. Seven working group meetings have been held to date and there is expectation that an instrument will emerge by the final deadline - the Tenth Meeting of the Conference of the Parties in Nagoya, Japan in October 2010. A key component singled out for inclusion in the international regime relates to the recognition and protection of the rights of indigenous and local communities (ILCs) over their traditional knowledge (TK) associated with genetic resources. The Ninth Meeting o...

2010-01-01

219

Heparin binding sites on Ross River virus revealed by electron cryo-microscopy  

International Nuclear Information System (INIS)

Cell surface glycosaminoglycans play important roles in cell adhesion and viral entry. Laboratory strains of two alphaviruses, Sindbis and Semliki Forest virus, have been shown to utilize heparan sulfate as an attachment receptor, whereas Ross River virus (RRV) does not significantly interact with it. However, a single amino acid substitution at residue 218 in the RRV E2 glycoprotein adapts the virus to heparan sulfate binding and expands the host range of the virus into chicken embryo fibroblasts. Structures of the RRV mutant, E2 N218R, and its complex with heparin were determined through the use of electron cryo-microscopy and image reconstruction methods. Heparin was found to bind at the distal end of the RRV spikes, in a region of the E2 glycoprotein that has been previously implicated in cell-receptor recognition and antibody binding.

2005-02-20

220

Head pose estimation in computer vision: a survey.  

Science.gov (United States)

The capacity to estimate the head pose of another person is a common human ability that presents a unique challenge for computer vision systems. Compared to face detection and recognition, which have been the primary foci of face-related vision research, identity-invariant head pose estimation has fewer rigorously evaluated systems or generic solutions. In this paper, we discuss the inherent difficulties in head pose estimation and present an organized survey describing the evolution of the field. Our discussion focuses on the advantages and disadvantages of each approach and spans 90 of the most innovative and characteristic papers that have been published on this topic. We compare these systems by focusing on their ability to estimate coarse and fine head pose, highlighting approaches that are well suited for unconstrained environments. PMID:19229078

2009-04-01

221

Footnotes to the patent game: how does homo ludens1 enforce patent rights in Hungary?  

British Library Electronic Table of Contents (United Kingdom)

Legal context Can we imagine the patent case as a play? As Johann Huizinga, the Dutch historian and cultural theorist writes, "The lawsuit can be regarded as a game of chance, a contest or a verbal battle." According to Huizinga, science is actually a play itself, thus scientific recognition is nothing more than the solution of a task of a play. In this context, a patent suit is nothing more than a play played with the play (in other words a `Game of the Game'). Key points and practical significance In our view in an ideal world the enforcement of patent rights should be a game of chess, where all the information is available to both players and the rules are simple and unquestionable. All players accept, understand and interpret the rules the same way. The referee has no role to play. How...

2011-01-01

222

Follow-up and diagnosis of recurrences after radio-chemotherapy of malignant head and neck tumors  

International Nuclear Information System (INIS)

339 CT und 95 MRT examinations in 210 partients were evaluated retrospectively to determine the value of CT and MRT for follow-up of head and neck tumors and for diagnosing recurrences. Semi-quantitative evaluation of tumor extent during and after radiotherapy showed advantages for MRT since changes induced by treatment, particularly oedema, produced less contrast loss in the images. CT had a sensitivity of 81% for the recognition of recurrences; this was 92% for MRT. Specificity for CT was 76% and for MRT 86%. Concerning the reliability of individual diagnostic criteria, space occupying lesions were the most valuable in CT diagnosis. For MRT, space occupying lesions and infiltration into neighbouring structures were of equal value. Because of differences in the nature of the signals, MRT proved better than CT in characterising recurrent masses and this improved the differentiation between scarring and local tumour recurrence. (orig.).

223

Entropy, similarity measure of interval-valued intuitionistic fuzzy sets and their applications  

British Library Electronic Table of Contents (United Kingdom)

In this paper we propose an entropy measure for interval-valued intuitionistic fuzzy sets, which generalizes three entropy measures defined independently by Szmidt, Wang and Huang, for intuitionistic fuzzy sets. We also give an approach to construct similarity measures using entropy measures for interval-valued intuitionistic fuzzy sets. In particular, the proposed entropy measure for interval-valued intuitionistic fuzzy sets can yield a similarity measure. Several illustrative examples are given to demonstrate the practicality and effectiveness of the proposed formulas. We apply the similarity measure to solve problems on pattern recognitions, multi-criteria fuzzy decision making and medical diagnosis.

2011-01-01

224

Education qualification levels and school careers of unilateral versus bilateral hearing aid users  

British Library Electronic Table of Contents (United Kingdom)

Objective: Analyse the difference in school careers and secondary school qualification levels between unilateral hearing aid users and bilateral hearing aid users. Study design: Retrospective questionnaire study. Setting: Postal-based questionnaire. Participants: Names of adults known to have been fitted with unilateral or bilateral hearing aids during childhood were retrieved. This resulted in 292 names. Participants were selected using the following criteria: availability of the medical record, presence of bilateral hearing loss, completed secondary school education, normal IQ and a minimum aided word-recognition score of 70% at 10 years of age. The questionnaire was sent to 50 potential participants of whom 40 responded, resulting in two groups comprising 19 unilateral and 21 bilateral ...

2007-01-01

225

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants  

International Nuclear Information System (INIS)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostic system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1992-01-01

226

Do Higher Hospital-wide Nurse Staffing Levels Reduce In-hospital Mortality in Elderly Patients with Hip Fractures: A Pilot Study  

British Library Electronic Table of Contents (United Kingdom)

Background There is increasing recognition that lower nurse staffing levels are associated with higher morbidity and mortality among medical and surgical patients. The degree to which this applies to elderly patients with hip fractures is unclear. Questions/purposes We conducted a pilot study using administrative data as an initial step in investigating the relationship between nurse staffing levels and in-hospital mortality among elderly patients with hip fractures. Patients and Methods We retrospectively reviewed administrative data for 13,343 patients 65?years or older with a primary diagnosis of hip fracture admitted to 39 Michigan hospitals between 2003 and 2006. We used logistic regression to calculate the change in predicted probability of in-hospital death conferred by differences ...

2011-01-01

227

Detection of behavioral alterations and learning deficits in mice lacking synaptophysin  

British Library Electronic Table of Contents (United Kingdom)

The integral membrane protein synaptophysin is one of the most abundant polypeptide components of synaptic vesicles. It is not essential for neurotransmission despite its abundance but is believed to modulate the efficiency of the synaptic vesicle cycle. Detailed behavioral analyses were therefore performed on synaptophysin knockout mice to test whether synaptophysin affects higher brain functions. We find that these animals are more exploratory than their wild type counterparts examining novel objects more closely and intensely in an enriched open field arena. We also detect impairments in learning and memory, most notably reduced object novelty recognition and reduced spatial learning. These deficits are unlikely caused by impaired vision, since all electroretinographic parameters measur...

2009-01-01

228

Design: voice activated door opener.  

Science.gov (United States)

A voice activated garage door opener was designed for a handicapped person to open a garage door without assistance. This design uses speech recognition of one word. The activating word that was chosen is "up". The frequency spectrum of "up" was captured on a soundboard and is the basis of this design. Filters are used to pick out three frequency bands in this spectrum. The output signals from these filters are then compared to three threshold voltages using voltage comparators. If the output signals from the filters are above the threshold voltages, the comparators go high. Monostable multivibrators are used on the output of the comparators to lengthen the high pulses. When all of the pulses from the monostable multivibrators are high at the same time, an AND gate output goes high. This high pulse activates the door opener. PMID:8329601

1993-01-01

229

Corrosion: Understanding the basics  

Energy Technology Data Exchange (ETDEWEB)

This new book presents a practical how to approach to understanding and solving the problems of corrosion of structural materials. Although it is written mainly for those having a limited technical background in corrosion, it also provides more experienced engineers with a useful overview of the principles of corrosion and can be used as a general guide for developing a corrosion-control program. Contents include: the effects and economic impact of corrosion; basic concepts important to corrosion; principles of aqueous corrosion; forms of corrosion: recognition and prevention; types of corrosive environments; corrosion characteristics of structural materials; corrosion control by proper design; corrosion control by materials selection; corrosion control by protective coatings and inhibitors; corrosion control by cathodic and anodic protection; corrosion testing and monitoring; techniques for diagnosis of corrosion failures; and glossary of corrosion-related terms.

2000-07-01

230

Core funding to ICRAF  

Environmental Research Database

ObjectivesThe vision The Centre's vision is a rural transformation in the developing world where smallholder households massively increase their use of trees in agricultural landscapes to improve their food security, nutrition, income, health, shelter, energy resources and environmental sustainability. This vision is founded upon three basic tenets: 1. The growing importance of trees and treebased systems in sustaining livelihoods and agroecosystems; 2. The Centre's experience and comparative adv [continued...]DescriptionBackground: The International Council for Research in Agroforestry (ICRAF) was created in response to a visionary study in the mid-1970s led by forester John Bene of Canada's International Development Research Centre (IDRC). The study coined the term 'agroforestry' and called for global recognition of the key role trees play on farms. This led to the establishment of ICRAF in 1978 to promote agroforestry research in developing countries. Intended ...

2016-01-31

231

Color recognition system for urine analyzer  

Science.gov (United States)

In order to increase the speed of photoelectric conversion, a linear CCD is applied as the photoelectric converter instead of the traditional photodiode. A white LED is used as the light source of the system. The color information of the urine test strip is transferred into the CCD through a reflecting optical system. It is then converted to digital signals by an A/D converter. The test results of urine analysis are obtained by a data processing system. An ARM microprocessor is selected as the CPU of the system and a CPLD is employed to provide a driving timing for the CCD drive and the A/D converter. Active HDL7.2 and Verilog HDL are used to simulate the driving timing of the CPLD. Experimental results show that the correctness rate of the test results is better than 90%. The system satisfies the requirements of the color information collection of urine analyzer.

2010-08-01

232

Clustering high dimensional data using subspace and projected clustering algorithms  

CERN Document Server

Problem statement: Clustering has a number of techniques that have been developed in statistics, pattern recognition, data mining, and other fields. Subspace clustering enumerates clusters of objects in all subspaces of a dataset. It tends to produce many over lapping clusters. Approach: Subspace clustering and projected clustering are research areas for clustering in high dimensional spaces. In this research we experiment three clustering oriented algorithms, PROCLUS, P3C and STATPC. Results: In general, PROCLUS performs better in terms of time of calculation and produced the least number of un-clustered data while STATPC outperforms PROCLUS and P3C in the accuracy of both cluster points and relevant attributes found. Conclusions/Recommendations: In this study, we analyze in detail the properties of different data clustering method.

2010-01-01

233

Capturing the value of coastal ecosystem services for poverty alleviation in East and Southern Africa  

Environmental Research Database

ObjectivesCoastal ecosystems in developing countries supply a diverse range of services to local communities and national economies, including fish production, protection against floods and storms and support to tourism. Multiple drivers of change are influencing the status of the ecosystems, most of which are anthropogenic (Brown et al., 2006). Managing coastal ecosystems requires recognition of the diverse range of uses and users, and coordination between structures and processes, many of which are curr [continued...]DescriptionCommitment to the management of coastal ecosystems through addressing both ecological and social objectives already exists in East and Southern Africa (Glavovic 2006; Gustavson et al. 2009). More understanding, however, of the ecosystem services of priority to the poor and to poverty alleviation would strengthen the capacity of these initiatives to deliver on poverty alleviation and resource sustainability. The coastal regions of Tanzania, ...

2010-01-31

234

Age and gender differences in various topographical orientation strategies  

British Library Electronic Table of Contents (United Kingdom)

Orientation in the environment can draw on a variety of cognitive strategies. We asked 634 healthy volunteers to perform a comprehensive battery administered through an internet website (www.gettinglost.ca), testing different orientation strategies in virtual environments to determine the effect of age and gender upon these skills. Older participants (46-67years of age) performed worse than younger participants (18-30 or 31-45years of age) in all orientation skills assessed, including landmark recognition, integration of body-centered information, forming association between landmarks and body turns, and the formation and use of a cognitive map. Among all tests, however, the ability to form cognitive maps resulted to be the significant factor best at predicting the individuals' age group. ...

2011-01-01

235

Unsteady transonic flow computations for AGARD two dimensional and three dimensional aeroelastic configurations  

Science.gov (United States)

Numerical results on aeroelastic standard configurations are presented. The methods used for two dimensional configurations include the small perturbations approach for inviscid flow, coupling methods for unseparated flow, coupling methods for unseparated or separated, laminar or turbulent boundary layers, and a numerical solution of the Euler equations for inviscid flow. The three dimensional configurations are studied by the transonic small disturbance approach. The detailed results are given.

1986-12-01

236

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

237

Structure of unilamellar vesicles: Numerical analysis based on small-angle neutron scattering data  

International Nuclear Information System (INIS)

The structure of polydispersed populations of unilamellar vesicles is studied by small-angle neutron scattering for three types of lipid systems, namely, single-, two-and four-component vesicular systems. Results of the numerical analysis based on the separated-form-factor model are reported.

2006-12-01

238

Strength evaluation of bellows subjected to torsion  

Energy Technology Data Exchange (ETDEWEB)

In this paper the stress due to torsion and the torsional buckling behavior of bellows are investigated through both theoretical and numerical analyses. The numerical solutions agree with the theoretical results very well in a wide range of dimensions and the number of convolutions. Based on these results, the framework of the design rule related to the torsion of bellows is proposed. (J.P.N.).

1992-11-01

239

Parahydrogen clusters: Numerical estimates and physical effects  

Energy Technology Data Exchange (ETDEWEB)

We study by means of Quantum Monte Carlo simulations based on the Worm Algorithm the low temperature (down to T = 0.05 K) properties of parahydrogen clusters comprising up to 40 molecules. Three different intermolecular interactions are employed: the Silvera-Goldman, the Buck and the Lennard-Jones potential. Despite important discrepancies observed in the numerical estimates of energy and superfluid fraction, the mechanism by which clusters melt at low T is independent of the particular choice of the potential, whose only effect is to alter the temperature scale.

2009-02-01

240

Numerical investigation of three-dimensional flows of steam-water mixture in the housing of the PGV-1000 steam generator  

British Library Electronic Table of Contents (United Kingdom)

Results are given of numerical simulation of three-dimensional pattern of flow of a two-phase steam-water mixture in the house of a PGV-1000 horizontal steam generator obtained using the BAGIRA best-estimate thermohydrodynamic computer codes. The space distributions of velocities and local void fractions in the steam generator housing for different modes of operation of power-generating unit are calculated and compared with available experimental data.

2008-01-01

241

Numerical investigation of three-dimensional flows of steam-water mixture in the housing of the PGV-1000 steam generator  

Science.gov (United States)

Results are given of numerical simulation of three-dimensional pattern of flow of a two-phase steam-water mixture in the house of a PGV-1000 horizontal steam generator obtained using the BAGIRA best-estimate thermohydrodynamic computer codes. The space distributions of velocities and local void fractions in the steam generator housing for different modes of operation of power-generating unit are calculated and compared with available experimental data.

2008-05-01

242

Numerical error analysis of direct integration method  

Energy Technology Data Exchange (ETDEWEB)

Numerical errors of PALLAS calculation due to spatial mesh sizes are examined for a typical deep penetration shielding problem of isotropic incident fission neutrons penetrating a 200-cm-thick water slab. The exponential approximation for the source spatial distribution to solve the transport equation based on the direct integration method is verified to be effective for radiation transport in attenuating medium, while the linear approximation employed in the old PALLAS code is found to produce large errors for calculations with large mesh sizes.

1986-01-01

243

Investigation of free-forced convection flows in cavity-type receivers  

Energy Technology Data Exchange (ETDEWEB)

A numerical calculation procedure applicable to cavity-type receiver configurations and flow conditions was developed. Flow visualization experiments were performed, and experimental measurements of quantities valuable for the development of the numerical calculation procedure were made. The investigation is focussed on a configuration which is strongly two-dimensional in the mean flow structure (but turbulent in a truly three-dimensional sense). (LEW)

1982-07-01

244

Explosive acceleration of liquid from a cylindrical container using the implosive technique  

British Library Electronic Table of Contents (United Kingdom)

Tthe acceleration of a liquid from a cylindrical container by the products of instantaneous detonation of a superimposed explosive charge (implosion method) is studies numerically in a two-dimensional formulation. Analytical formulas for the asymptotic velocities of liquid expansion and acceleration of the container body were obtained using numerical calculations in a one-dimensional approximation. The effect of the fracture of the body on the velocity of liquid expansion was studied in a two-dimensional formulation.

2011-01-01

245

Collisional-radiative model for highly stripped ions  

Energy Technology Data Exchange (ETDEWEB)

Collisional-Radiative numerical models are commonly used to design or interpret experiments in atomic physics of laser-created plasmas, including X-ray laser studies. We describe our new code containing several options: average ion, more or less detailed configurations. It consists of an atomic data base coupled to subroutines evaluating ionic populations and emission and absorption coefficients. Numerical results are given to illustrate the capabilities of the code and to compare different models and types of approximation.

1986-10-01

246

An idealized numerical simulation of mammatus-like clouds  

British Library Electronic Table of Contents (United Kingdom)

A three-dimensional numerical simulation of mammatus-like clouds is presented. A portion of a cirrus outflow anvil cloud is simulated including cloud ice and snow microphysical representations. The simulated mammatus clouds appear in a cellular pattern and are compared with the few available previously published physical observations of mammatus. Copyright Copyright 2006 Royal Meteorological Society

2006-01-01

247

3-D numerical simulation of the transient electromagnetic pulse coupling to double cylinder object  

International Nuclear Information System (INIS)

In this paper, finite-difference time-domain method is used to research the transient electromagnetic pulse (EMP) coupling to the cylinder object which is shielded in another shielding cavity with a hole numerically. The different coupling effectiveness of three transient EMP is simulated. The distribution of the electric field in the shielding cavity and the current on the cavity are researched. The shielding effectiveness is evaluated. (authors)

2006-10-21

248

Numerical Simulation and Analyses of the Loss of Feedwater Transient at the Unit 4 of Kola NPP  

Science.gov (United States)

A three-dimensional numerical simulation of the loss-of-feed water transient at the horizontal steam generator of the Kola nuclear power plant is performed. Presented numerical results show transient change of integral steam generator parameters, such as steam generation rate, water mass inventory, outlet reactor coolant temperature, as well as detailed distribution of shell side thermal-hydraulic parameters: swell and collapsed levels, void fraction distributions, mass flux vectors, etc. Numerical results are compared with measurements at the Kola NPP. The agreement is satisfactory, while differences are close to or below the measurement uncertainties. Obtained numerical results are the first ones that give complete insight into the three-dimensional and transient horizontal steam generator thermal-hydraulics. Also, the presented results serve as benchmark tests for the assessment and further ...

2002-07-01

249

Elimination of numerical dispersion in finite-difference modeling and migration by flux-corrected transport  

Energy Technology Data Exchange (ETDEWEB)

Finite-difference acoustic-wave modeling and reverse-time depth migration based on the full wave equation are general approaches that can take into account arbitrary variations in velocity and density and can handle turning waves as well. However, conventional finite-difference methods for solving the acoustic- or elastic-wave equation suffer from numerical dispersion when too few samples per wavelength are used. The flux-corrected transport (FCT) algorithm, adapted from hydrodynamics, reduces the numerical dispersion in finite-difference wavefield continuation. The flux-correction procedure endeavors to incorporate diffusion into the wavefield continuation process only where needed to suppress the numerical dispersion. Incorporating the flux-correction procedure in conventional finite-difference modeling or reverse-time migration can provide finite-difference solutions with no numerical dispersion even ...

1995-11-01

250

ATRX ADD domain links an atypical histone methylation recognition mechanism to human mental-retardation syndrome  

Energy Technology Data Exchange (ETDEWEB)

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at pericentromeric heterochromatin; ...

2011-07-19

251

Test of a numerical optimization algorithm for obtaining cross sections for multiple collision processes from electron swarm data  

Energy Technology Data Exchange (ETDEWEB)

A numerical optimization technique is used to obtain low-energy momentum transfer, j = 0 [yields] 2 rotational and v = 0 [yields] vibrational sections from measured electron swarm data for parahydrogen. The downhill simplex algorithm is used to find cross sections that represent the best numerical fit to the measured electron drift velocity and characteristic energy over a range of E/N. These results, which are in excellent agreement with published cross sections derived using traditional swarm analysis techniques, demonstrates the feasibility of using automated computational algorithms for swarm analysis involving the estimation of multiple cross sections. (Author).

1993-02-14

252

Stability of the viscously spreading ring  

CERN Document Server

We study analytically and numerically the stability of the pressure-less, viscously spreading accretion ring. We show that the ring is unstable to small non-axisymmetric perturbations. To perform the perturbation analysis of the ring we use a stretching transformation of the time coordinate. We find that to 1st order, one-armed spiral structures, and to 2nd order additionally two-armed spiral features may appear. Furthermore, we identify a dispersion relation determining the instability of the ring. The theoretical results are confirmed in several simulations, using two different numerical methods. These computations prove independently the existence of a secular spiral instability driven by viscosity, which evolves into persisting leading and trailing spiral waves. Our results settle the question whether the spiral structures found in earlier simulations of the spreading ring are numerical artifacts or genuine ...

2003-01-01

253

Numerical simulations of nucleate boiling in impinging jets: Applications in power electronics cooling  

Energy Technology Data Exchange (ETDEWEB)

Boiling jet impingement cooling is currently being explored to cool power electronics components. In hybrid vehicles, inverters are used for DC-AC conversion. These inverters involve a number of insulated-gate bipolar transistors (IGBTs), which are used as on/off switches. The heat dissipated in these transistors can result in heat fluxes of up to 200 W/cm{sup 2}, which makes the thermal management problem quite important. In this paper, turbulent jet impingement involving nucleate boiling is explored numerically. The framework for these computations is the CFD code FLUENT. For nucleate boiling, the Eulerian multiphase model is used. The numerical results for boiling water and R113 jets (submerged) are validated against existing experimental data in the literature. Some representative IGBT package simulations that use R134a as the cooling fluid are also presented. (author)

2008-01-15

254

Numerical simulation of fluid flow and heat transfer in a concentric tube heat exchanger  

International Nuclear Information System (INIS)

In this paper, numerical simulation of a concentric tube heat exchanger is presented to determine the convective heat transfer coefficient and friction factor in a smooth tube. Increasing the convective heat transfer coefficient can increase heat transfer rate in a concentric tube heat exchanger from a given tubular surface area. This can be achieved by using heat transfer augmentation devices. This work constitutes the initial phase of the numerical simulation of heat transfer from tubes employing augmentation devices, such as twisted tapes, wire-coil inserts, for heat transfer enhancement. A computational fluid dynamics (CFD) simulation tool was developed with CFX software and the results obtained from the simulations are validated with the empirical correlations for a smooth tube heat exchanger. The difficulties associated with the simulation of a heat exchanger augmented with wire-coil inserts are discussed. (author)

2003-05-28

255

Numerical simulation of coalbed methane generation, dissipation and retention in SE edge of Ordos Basin, China  

British Library Electronic Table of Contents (United Kingdom)

This paper presents a numerical study on the formation history of coalbed methane (CBM) reservoir in the southeast edge of Ordos Basin, China. The coal seams studied belong to the Late Palaeozoic coal-bearing series. These coal seams have a burial history and experienced the process of subsidence, rapid subsidence alternated with uplift and then uplift, sequentially, and underwent the geothermal actions at normal, extremely high, and then normal temperatures, respectively. Coal organic matter of the coal seams matured in the Triassic Period and in the Late Jurassic to Early Cretaceous Period. The results from numerical simulation reveal that CBM reservoir evolution history can be classified into five stages, namely primary, initial, stagnant, active and dissipative stages. In the first (pr...

2010-01-01

256

Numerical simulation and experimental analysis for a Risers Uphold Sub-Surface Buoy (BSR); Simulacao numerica e ensaio experimental da Boia de Sub-superficie de Suporte de Risers - BSSR  

Energy Technology Data Exchange (ETDEWEB)

This paper presents results, numeric and experimental, due to installation operation of a Risers Uphold Sub-Surface Buoy, (BSR). This kind of installation developed by PETROBRAS is unique in the world. The work of BSR installation was based on a numeric pre analysis to verify the system and determine the main parameters to be experimentally verified. The second phase of the work was the experimental analysis in a deep water ocean basin. s. The work describes the BSR and their main accessories, the experimental environment and the model constructed in aluminum in a 1:12 scale and the main results. (author)

2004-07-01

257

Numerical analysis of methane-air combustion considering radiation effect  

Energy Technology Data Exchange (ETDEWEB)

Turbulent premixed methane-air combustion in a cylindrical chamber is numerically simulated considering radiation effect. Reaction rates are considered as minimum rates between Arrhenius rates and eddy break up rates. A five step reduced mechanism is used. Turbulent modeling is done via standard k-{epsilon} model imposed by empirical inlet boundary conditions. Source terms of energy equation consist of reaction rates and radiation effects. The discrete ordinate method (DOM) is employed to solve the radiative transfer equation (RTE) and the weighted sum of gray gas model (WSGGM) is imposed to consider radiation effect of non-gray gases. The results indicate that in the case of turbulent combusting flows, the effect of radiation of gases can affect the temperature and species concentrations. The numerical results obtained considering radiation effect are closer to the experimental data than that of the case without radiation effect. (author)

2008-12-15

258

Numerical analysis of methane-air combustion considering radiation effect  

International Nuclear Information System (INIS)

Turbulent premixed methane-air combustion in a cylindrical chamber is numerically simulated considering radiation effect. Reaction rates are considered as minimum rates between Arrhenius rates and eddy break up rates. A five step reduced mechanism is used. Turbulent modeling is done via standard k-? model imposed by empirical inlet boundary conditions. Source terms of energy equation consist of reaction rates and radiation effects. The discrete ordinate method (DOM) is employed to solve the radiative transfer equation (RTE) and the weighted sum of gray gas model (WSGGM) is imposed to consider radiation effect of non-gray gases. The results indicate that in the case of turbulent combusting flows, the effect of radiation of gases can affect the temperature and species concentrations. The numerical results obtained considering radiation effect are closer to the experimental data than that of the case without radiation effect.

2008-12-01

259

Cross-count identity, distinctness, and the theory of internal and external relations  

British Library Electronic Table of Contents (United Kingdom)

Baxter (Australas J Philos 79:449?464, 2001) proposes an ingenious solution to the problem of instantiation based on his theory of cross-count identity. His idea is that where a particular instantiates a universal it shares an aspect with that universal. Both the particular and the universal are numerically identical with the shared aspect in different counts. Although Baxter does not say exactly what a count is, it appears that he takes ways of counting as mysterious primitives against which different numerical identities are defined. In contrast, I defend the idea?suggested, though not quite endorsed, by Baxter himself?that counts are independent dimensions of numerical identity. Different ways of counting are explained by the existence of these different sorts of identity (i.e., counts)...

2010-01-01

260

Constructing a Mass-Current Radiation-Reaction Force For Numerical Simulations  

CERN Document Server

We present a new set of 3.5 Post-Newtonian equations in which Newtonian hydrodynamics is coupled to the nonconservative effects of gravitational radiation emission. Our formalism differs in two significant ways from a similar 3.5 Post-Newtonian approach proposed by Blanchet (1993, 1997). Firstly we concentrate only on the radiation-reaction effects produced by a time-varying mass-current quadrupole $S_{ij}$. Secondly, we adopt a gauge in which the radiation-reaction force densities depend on the fourth time derivative of $S_{ij}$, rather than on the fifth, as in Blanchet's approach. This difference makes our formalism particularly well-suited to numerical implementation and could prove useful in performing fully numerical simulations of the recently discovered $r$-mode instability for rotating neutron stars subject to axial perturbations.

1999-01-01

261

Comparison of a cavity solar receiver numerical model and experimental data  

Energy Technology Data Exchange (ETDEWEB)

Results from a numerical model of axisymmetric solar cavity receivers are compared with experimental data for tests of a novel test bed receiver in the Saudi National Laboratories solar furnace. The computed energy transfer rates and temperatures are compared with the experimental data for different receiver geometries, aperture sizes, and operating conditions. In general, the agreement between the numerical model and the experimental data is better for the small-to-midsized apertures than for the large apertures. The analysis indicates that for the larger apertures, the convective heat losses are overpredicted. It also suggests that these losses could be better characterized. Sensitivity analyses show that both the total solar energy input rate and the convective heat-loss coefficient significantly affect the receiver thermal performance and that the distribution of the input solar flux significantly affects the temperature distribution in the ...

1990-08-01

262

Comparison of Galerkin and control volume finite element for advection-diffusion problems.  

Energy Technology Data Exchange (ETDEWEB)

The control volume finite element method (CVFEM) was developed to combine the local numerical conservation property of control volume methods with the unstructured grid and generality of finite element methods (FEMs). Most implementations of CVFEM include mass-lumping and upwinding techniques typical of control volume schemes. In this work we compare, via numerical error analysis, CVFEM and FEM utilizing consistent and lumped mass implementations, and stabilized Petrov-Galerkin streamline upwind schemes in the context of advection-diffusion processes. For this type of problem, we find no apparent advantage to the local numerical conservation aspect of CVFEM as compared to FEM. The stabilized schemes improve accuracy and degree of positivity on coarse grids, and also reduce iteration counts for advection-dominated problems.

2005-03-01

263

An anisotropic mesh adaptation method for the finite element solution of heterogeneous anisotropic diffusion problems  

CERN Document Server

Heterogeneous anisotropic diffusion problems arise in the various areas of science and engineering including plasma physics, petroleum engineering, and image processing. Standard numerical methods can produce spurious oscillations when they are used to solve those problems. A common approach to avoid this difficulty is to design a proper numerical scheme and/or a proper mesh so that the numerical solution validates the discrete counterpart (DMP) of the maximum principle satisfied by the continuous solution. A well known mesh condition for the DMP satisfaction by the linear finite element solution of isotropic diffusion problems is the non-obtuse angle condition that requires the dihedral angles of mesh elements to be non-obtuse. In this paper, a generalization of the condition, the so-called anisotropic non-obtuse angle condition, is developed for the finite element solution of heterogeneous anisotropic diffusion problems. ...

2010-01-01

264

An Accurate Numerical Solution to the Kinetics of Breakable Filament Assembly  

CERN Document Server

Proteinaceous aggregation occurs through self-assembly-- a process not entirely understood. In a recent article [1], an analytical theory for amyloid fibril growth via secondary rather than primary nucleation was presented. Remarkably, with only a single kinetic parameter, the authors were able to unify growth characteristics for a variety of experimental data. In essence, they seem to have uncovered the underlying allometric laws governing the evolution of filament elongation simply from two coupled non-linear ordinary differential equations (ODEs) stemming from a master equation. While this work adds significantly to our understanding of filament self-assembly, it required an approximate analytical solution representation. Here, we show that the same results are found by purely numerical means once a straightforward and reliable numerical solution to the set of ODEs has been established.

2010-01-01

265

A numerical study of ultra-short-pulse reflectometry  

Energy Technology Data Exchange (ETDEWEB)

Ultra-short-pulse reflectometry is studied by means of the numerical integration of a one-dimensional full-wave equation for ordinary modes propagating in a plasma. The numerical calculations illustrate the potential of using the reflection of ultra-short-pulse, microwaves as an effective probe of the density profile even in the presence of significant density fluctuations. The difference in time delays of differing frequency components of the microwaves can be used to deduce the density profile. The modification of the reflected pulses in the presence of density fluctuations is examined and can be understood based on considerations of Bragg resonance. A simple and effective profile-reconstruction algorithm using the zero-crossings of the reflected pulse and subsequent Abel inversion is demonstrated. The robustness of the profile reconstruction algorithm in the presence of a sufficiently small amplitude density perturbation is assessed.

1994-05-01

266

A combined numerical and theoretical study on the penetration of a jacketed rod into semi-infinite targets  

British Library Electronic Table of Contents (United Kingdom)

A combined numerical and theoretical study is conducted herein on the penetration of semi-infinite targets by jacketed rods with different r"j"0/r"c"0 ratios where r"j"0 and r"c"0 are the radii of the jacket and the core, respectively. The numerical results show that for smaller r"j"0/r"c"0 ratios the u-v relationship changes only a little compared to that of unitary long rod penetrator of the same core material, hence, the u-v relationship of unitary (homogeneous) long rod penetration is also applicable for jacketed rod penetration. Model for cratering in semi-infinite targets by jacketed rods is then suggested by using the laws of conversation of mass, momentum and energy, together with the u-v relationship of unitary (homogeneous) long rod penetration and an analytical model for predict...

2011-01-01

267

3D modelling as a support to thermal-hydraulic safety analyses with standard codes  

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional (3D) thermal-hydraulic model and a numerical procedure for the simulation and analysis of a steady-state, as well as transient operation of nuclear power plant components are presented. A two-fluid approach is applied to modelling of two-phase flow. Thermal-hydraulics of a horizontal steam generator in the WWER 1000 nuclear power plant has been simulated at the full load, steady-state operation. A comparison of the numerical results with data measured at the NPP Novovoronjezh shows good agreement. 3D numerical results can be used in plant design or retrofitting, in nuclear power plant operation and safety analysis and as improvement of existing one-dimensional thermal-hydraulics models of the horizontal steam generator which are assessed by system codes used for the nuclear power plant safety analyses. (author)

1999-07-01

268

3D modelling as a support to thermal-hydraulic safety analyses with standard codes  

International Nuclear Information System (INIS)

A three-dimensional (3D) thermal-hydraulic model and a numerical procedure for the simulation and analysis of a steady-state, as well as transient operation of nuclear power plant components are presented. A two-fluid approach is applied to modelling of two-phase flow. Thermal-hydraulics of a horizontal steam generator in the WWER 1000 nuclear power plant has been simulated at the full load, steady-state operation. A comparison of the numerical results with data measured at the NPP Novovoronjezh shows good agreement. 3D numerical results can be used in plant design or retrofitting, in nuclear power plant operation and safety analysis and as improvement of existing one-dimensional thermal-hydraulics models of the horizontal steam generator which are assessed by system codes used for the nuclear power plant safety analyses. (author)

1999-04-19

269

skittles, a Drosophila phosphatidylinositol 4-phosphate 5-kinase, is required for cell viability, germline development and bristle morphology, but not for neurotransmitter release.  

UK PubMed Central (United Kingdom)

The phosphatidylinositol pathway is implicated in the regulation of numerous cellular functions and responses to extracellular signals. An important branching point in the pathway is the phosphorylation...Full Text Available

1998-12-01

270

p53 Regulates Oxidative Stress-Mediated Retrograde Signaling: A Novel Mechanism for Chemotherapy-Induced Cardiac Injury  

UK PubMed Central (United Kingdom)

The side effects of cancer therapy on normal tissues limit the success of therapy. Generation of reactive oxygen species (ROS) has been implicated for numerous chemotherapeutic agents including doxorubicin...Full Text Available

271

Zinc release from thapsigargin/IP3-sensitive stores in cultured cortical neurons  

UK PubMed Central (United Kingdom)

BackgroundChanges in ionic concentration have a fundamental effect on numerous physiological processes. For example, IP3-gated thapsigargin sensitive intracellular calcium...Full Text Available

272

WESTEX: A Numerical, One Dimensional Reservoir Thermal ...  

Science.gov (United States)

... al - 3.9863 a 2 - 508929.2 a3 - 288.994 a4 - 68.129 13. It is apparent from Figure I and Equation 1 that when water temper- ...

1993-08-01

273

Virological and serological surveillance for type A influenza in the black-legged kittiwake (Rissa tridactyla)  

UK PubMed Central (United Kingdom)

BackgroundThe epidemiology of avian influenza viruses (AIVs) in gulls is only partially known. The role of the world's most numerous gull species, the black-legged kittiwake (Rissa...Full Text Available

274

Viewpoint: Policy Requirements for Protecting Wildlife from Endocrine Disruptors  

UK PubMed Central (United Kingdom)

Man-made endocrine-disrupting chemicals (EDCs) present a threat to biodiversity, even in remote areas. To date, numerous wildlife species have been affected by EDCs in the environment, but it is likely...Full Text Available

2006-04-01

275

Ultrasmall spot size scanning laser ophthalmoscopy  

UK PubMed Central (United Kingdom)

An ultrasmall spot size scanning laser ophthalmoscope has been developed that employs an annular aberration-corrected incident beam to increase the effective numerical aperture of the eye thereby reducing...Full Text Available

276

Transient radon diffusion through radon-proof membranes: A new technique for more precise determination of the radon diffusion coefficient  

Energy Technology Data Exchange (ETDEWEB)

The following paper is focused on the numerical modelling of the transient radon diffusion through radon-proof membranes during the measurement of their radon diffusion coefficient. The major aim of such numerical modelling is to increase the accuracy of radon diffusion coefficients derived from the measured data sets. The developed complex ''transient'' numerical model is able to calculate the radon diffusion coefficient with sufficient accuracy from almost any data set - even from a short-time measurement with a non-linear course of results. This numerical model can also be used for various analyses of transient radon transfer processes (e.g. for the calculation of radon distribution curves within the membrane). The following paper presents governing equations for the simulation model, together with a brief description of algorithms incorporated in the newly ...

2009-06-15

277

Theoretical study of lithium isotope separation by displacement chromatography  

Energy Technology Data Exchange (ETDEWEB)

Lithium isotope separation by displacement chromatography is studied using fundamental principles; the equations are derived assuming theoretical stages in lithium adsorption bands. The concentration profiles in the band are calculated numerically under unsteady state.

1982-01-01

278

The influence of the explosion of the conductor of an electric cable on the dielectric properties of the polymer insulator  

British Library Electronic Table of Contents (United Kingdom)

The electric explosion of a conductor being part of an electric cable is studied. It is ascertained that the electric properties of a polymeric dielectric depend nonlinearly on the maintenance of the ultradisperse metal filler. In the course of the numerous heating-cooling processes of an insulator, a streamlining of the structure of a polymeric composite occurs.

2010-01-01

279

The Stability and Formation of Native Proteins from Unfolded Monomers Is Increased through Interactions with Unrelated Proteins  

UK PubMed Central (United Kingdom)

The intracellular concentration of protein may be as high as 400 mg per ml; thus it seems inevitable that within the cell, numerous protein-protein contacts are constantly occurring. A basic biochemical...Full Text Available

280

Subjective scaling of spatial room acoustic parameters influenced by visual environmental cues  

UK PubMed Central (United Kingdom)

Although there have been numerous studies investigating subjective spatial impression in rooms, only a few of those studies have addressed the influence of visual cues on the judgment of auditory measures....Full Text Available

2010-10-01

281

Subject-specific, multiscale simulation of electrophysiology: a software pipeline for image-based models and application examples  

UK PubMed Central (United Kingdom)

Many simulation studies in biomedicine are based on a similar sequence of processing steps, starting from images and running through geometric model generation, assignment of tissue properties, numerical...Full Text Available

2009-06-13

282

Sediments transport and balance in coastal line; Trasporto solido ed equiliberio della linea di costa  

Energy Technology Data Exchange (ETDEWEB)

The erosion phenomena of coastal regions in Italy and in the world is remarkable from the environmental point of view. Are showed activities of mechanical defense and numerical models to solve complex problem.

1996-11-01

283

Role of histone methylation and demethylation in adipogenesis and obesity  

UK PubMed Central (United Kingdom)

Adipocyte differentiation is a complex developmental process that involves the coordinated interplay of numerous transcription factors. PPARγ has emerged as a master regulator of adipogenesis...Full Text Available

2010-01-01

284

Regulation of Mixed Lineage Kinase 3 is Required for Neurofibromatosis-2-Mediated Growth Suppression in Human Cancer  

UK PubMed Central (United Kingdom)

The Neurofibromatosis-2 (NF2) tumor suppressor merlin negatively regulates cell proliferation in numerous cell types. We have previously shown that the NF2...Full Text Available

2011-02-17

285

Quantification of physical and biological uncertainty in the simulation of the yield of a tropical crop using present-day and doubled CO2 climates  

UK PubMed Central (United Kingdom)

The impacts of climate change on crop productivity are often assessed using simulations from a numerical climate model as an input to a crop simulation model. The precision of these predictions reflects...Full Text Available

2005-11-29

286

QUT - 2008 winners  

Wastenet

... His work has been recognised with numerous honours, including Fellow of the Australian Academy of Science; International Research Scholarships from the Howard Hughes Medical Institute ; a Wellcome Trust Fellowship; the Glaxo-Wellcome Australia Medal; the Australian Academy of Science Gottschalk Medal; the Boehringer Mannheim Medal;...

287

Pyridinium based amphiphilic hydrogelators as potential antibacterial agents  

UK PubMed Central (United Kingdom)

SummaryThe numerous applications of hydrogelators have led to rapid expansion of this field. In the present work we report the facile synthesis of amphiphilic hydrogelators having a quaternary...Full Text Available

288

Pulsatile viscous flow in a curved pipe: Effects of pulsation on the development of secondary flow  

International Nuclear Information System (INIS)

This work presents an experimental and numerical study of pulsated Dean flow, three-dimensional pulsatile flow in a curved pipe. The numerical study is performed by CFD code (Fluent 6) in which a pulsated velocity field is imposed as an inlet condition. The experimental setup involves principally a 'Scotch-yoke' pulsatile generator and a 90o bend. Laser Doppler Velocimetry (LDV) measurements have shown that the Scotch-yoke generator produces pure sinusoidal instantaneous mean velocities with a mean deviation of 3%. Visualizations by laser-induced fluorescence (LIF) and velocity measurements, coupled with the numerical results, have permitted analysis of the evolution of the swirling secondary flow structures that develop along the bend during the pulsation phase. These measurements were made for a range of stationary Reynolds number (300?Rest?1200), frequency parameter (1??=r0(?/?)1/2max,osc/Ust). We observe satisfactory ...

2010-10-01

289

Particulate allergens potentiate allergic asthma in mice through sustained IgE-mediated mast cell activation  

UK PubMed Central (United Kingdom)

Allergic asthma is characterized by airway hyperresponsiveness, inflammation, and a cellular infiltrate dominated by eosinophils. Numerous epidemiological studies have related the exacerbation of allergic...Full Text Available

2011-03-01

290

Optical System Assessment for Design: Numerical Ray Tracing in the Gaussian Pupil,  

Science.gov (United States)

The continuing rapid increase in available computing power has not reduced the importance of efficient methods of optical system assessment for automatic lens design. On the contrary, the new capabilities simply show that truly automatic optical design wi...

1988-01-01

291

Numerical simulations of quantized Bianchi type IX cosmological models  

International Nuclear Information System (INIS)

This paper reports on Monte Carlo path integral simulations of a Bianchi Type IX cosmology which yield a wave function which reflects the known chaotic dynamics of the classical system and predicts a significant probability for a correlation between large universe volume and large anisotropy.

1988-08-08

292

Numerical optimization of spherical variable-line-spacing grating X-ray spectrometers  

UK PubMed Central (United Kingdom)

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and...Full Text Available

2011-03-01

293

Numerical modeling of slug flow initiation in a horizontal channels using a two-fluid model  

International Nuclear Information System (INIS)

This paper presents a methodology for modeling slug initiation and growth in horizontal ducts. Transient two-fluid equations are solved numerically using a class of high-resolution shock capturing methods. The advantage of this method is that slug formation and growth in a stratified regime can be calculated directly from the solutions to the flow field differential equations. In addition, by using high-resolution shock capturing methods that do not contain numerical diffusion, the discontinuity generated by slugging in the flow field can be modeled with good accuracy. The two-fluid model is shown to be well-posed mathematically only under certain conditions. Under these circumstances, the two-fluid model is capable of correctly predicting and modeling the flow physics. When ill-posed, an unbounded instability occurs in the flow field solution, and the instability amplitude increases exponentially with decreasing mesh sizes. This work shows ...

2011-02-01

294

Numerical analysis of natural convection in a square cavity at high Rayleigh numbers using the GSMAC finite-element method. GSMAC yugen yosoho ni yoru ko Rayleigh su seihokei cavity nai shizen tairyu no hi teijo kaiseki  

Energy Technology Data Exchange (ETDEWEB)

Stable and accurate numerical analytical method even at high Rayleigh numbers is desired, and in addition flexibility and economical efficiency are very important for numerical analysis. Unsteady flows of natural convention in a square cavity are investigated using the GSMAC (generalized and simplified marker and cell) finite-element method at high Rayleigh numbers from 10 {sup 6} to 10 {sup 8}. Validities of the multi-pass algorithm and BTD (balancing tensor diffusivity), which are highly accurate solutions for finite-element method, are investigated by introducing them to the GSMAC finite-element method. As the result, it was found that the multi-pass algorithm has little effect for the GSMAC finite-element method. The steady solutions at the Rayleigh numbers of 10 {sup 5} and 10 {sup 7} agreed well with the bench mark solutions and numerical solutions. Complex transient phenomena at Rayleigh numbers higher than 10 {sup ...

1990-10-25

295

Northern blotting analysis of microRNAs, their precursors and RNA interference triggers  

UK PubMed Central (United Kingdom)

BackgroundNumerous microRNAs (miRNAs) have heterogeneous ends resulting from imprecise cleavages by processing nucleases and from various non-templated nucleotide additions. The...Full Text Available

296

Mean distance of closest approach of alkaline-earth metals ions in aqueous solutions: Experimental and theoretical calculations  

British Library Electronic Table of Contents (United Kingdom)

The estimation of numerical values of the mean distance of closest approach of ions, a, of alkaline-earth metal ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.

2010-01-01

297

Low level of polymorphism in two putative NPR1 homologs in the Vitaceae family  

UK PubMed Central (United Kingdom)

BackgroundGrapevine is subjected to numerous pests and diseases resulting in the use of phytochemicals in large quantities. The will to decrease the use of phytochemicals leads to...Full Text Available

298

Lineage-specific co-evolution of the Egf receptor/ligand signaling system  

UK PubMed Central (United Kingdom)

BackgroundThe epidermal growth factor receptor (Egfr) with its numerous ligands has fundamental roles in development, cell differentiation and physiology. Dysfunction of the receptor-ligand...Full Text Available

299

JPL Air Sea Interaction & Climate Team - Data  

Science.gov (United States)

provides global ocean-surface wind fields with more structures than numerical weather prediction (Geophys. Res. Lett., Vol 25, No. 6, 761-764). The NSCAT data sets was produced...

2011-08-26

300

Isolation of BAC Clones Containing Conserved Genes from Libraries of Three Distantly Related Moths: A Useful Resource for Comparative Genomics of Lepidoptera  

UK PubMed Central (United Kingdom)

Lepidoptera, butterflies and moths, is the second largest animal order and includes numerous agricultural pests. To facilitate comparative genomics in Lepidoptera, we isolated BAC clones containing...Full Text Available

2011-01-01

301

Insecticide resistance resulting from sequential selection of houseflies in the field by organophosphorus compounds*  

UK PubMed Central (United Kingdom)

Although cross-resistance in houseflies to the organophosphates has eliminated numerous potentially useful compounds from field use, the ”subgroup” specificity of this phenomenon has...Full Text Available

1971-01-01

302

Information circulars  

International Nuclear Information System (INIS)

Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to mid-August 1994. A complete numerical list of information circulars is reproduced with their titles in the Annex.

2005-08-01

303

Identification of a distant cis-regulatory element controlling pharyngeal arch-specific expression of zebrafish gdf6a/radar  

UK PubMed Central (United Kingdom)

Skeletal formation is an essential and intricately regulated part of vertebrate development. Humans and mice deficient in Growth and Differentiation Factor 6 (Gdf6) have numerous...Full Text Available

2010-04-01

304

Hydrodynamics of primordial black hole formation: dependence on the equation of state  

Energy Technology Data Exchange (ETDEWEB)

An analysis is made of the manner in which the process of primordial black-hole formation and the subsequent accretion of gas depend on the equation of state. On the assumption that the process is spherically symmetric, the problem is solved numerically.

1980-03-01

305

How Protein Stability and New Functions Trade Off  

UK PubMed Central (United Kingdom)

Numerous studies have noted that the evolution of new enzymatic specificities is accompanied by loss of the protein's thermodynamic stability (ΔΔG), thus suggesting...Full Text Available

2008-02-01

306

Effects of Human Adipose-derived Stem Cells on Cutaneous Wound Healing in Nude Mice  

UK PubMed Central (United Kingdom)

BackgroundDespite numerous treatments available for deteriorated cutaneous wound healing such as a diabetic foot, there is still the need for more effective therapy. Adipose-derived...Full Text Available

2011-05-01

307

ESTIMATION OF WATER QUALITY CRITERIA VIOLATION FREQUENCIES USING PEARSON PERCENTILES  

Science.gov (United States)

A numerical technique is developed for estimating water quality violation frequencies due to pollutant discharges from urban areas during combined sewer overflow events. The first four moments of in-stream pollutant concentration are found by integrating a pollutant loading - wat...

308

Differential interleukin-6/Stat3 signaling as a function of cellular context mediates Ras-induced transformation  

UK PubMed Central (United Kingdom)

IntroductionTyrosine phosphorylated signal transducer and activator of transcription 3 (pStat3) is expressed in numerous cancers and is required for mediating tumorigenesis. Autocrine...Full Text Available

2010-01-01

309

Developmental toxicity and structure/activity correlates of glycols and glycol ethers.  

UK PubMed Central (United Kingdom)

In recent years, the National Toxicology Program (NTP) has selected numerous glycol ethers for testing in routine laboratory mammals to ascertain the magnitude of their ability to injure the conceptus....Full Text Available

1984-08-01

310

Developmental gene regulation during tomato fruit ripening and in-vitro sepal morphogenesis  

UK PubMed Central (United Kingdom)

BackgroundRed ripe tomatoes are the result of numerous physiological changes controlled by hormonal and developmental signals, causing maturation or differentiation of various fruit...Full Text Available

311

Ct3d: tracking microglia motility in 3D using a novel cosegmentation approach  

UK PubMed Central (United Kingdom)

Motivation: Cell tracking is an important method to quantitatively analyze time-lapse microscopy data. While numerous methods and tools exist for tracking cells in 2D time-lapse images,...Full Text Available

2011-02-15

312

Clostridium perfringens Delta Toxin Is Sequence Related to Beta Toxin, NetB, and Staphylococcus Pore-Forming Toxins, but Shows Functional Differences  

UK PubMed Central (United Kingdom)

Clostridium perfringens produces numerous toxins, which are responsible for severe diseases in man and animals. Delta toxin is one of the three hemolysins released by a number of C....Full Text Available

313

Climatology: An atmospheric science  

Energy Technology Data Exchange (ETDEWEB)

In this college-level introductory text the authors outline the fundamental principles of meteorology. The text is divided into three sections: meteorology, regionalization of climate, and climate change. Numerous charts, graphs, and photographs are displayed with each subject. A glossary of terms is also provided at the end of the book.

1993-01-01

314

Characterization of ?-Butyrolactone Autoregulatory Signaling Gene Homologs in the Angucyclinone Polyketide WS5995B Producer Streptomyces acidiscabies?  

UK PubMed Central (United Kingdom)

Organisms belonging to the genus Streptomyces produce numerous important secondary metabolites and undergo a sophisticated morphological differentiation program. In many instances these...Full Text Available

2009-08-01

315

CXCL12-Mediated Guidance of Migrating Embryonic Stem Cell-Derived Neural Progenitors Transplanted into the Hippocampus  

UK PubMed Central (United Kingdom)

Stem cell therapies for neurodegenerative disorders require accurate delivery of the transplanted cells to the sites of damage. Numerous studies have established that fluid injections to the hippocampus...Full Text Available

316

Assessment of the value of various tomography modalities for diagnostic evaluation of the female genital system  

International Nuclear Information System (INIS)

The comprehensive survey explains the indications and the specific value of the modern tomographic modalities with respect to the various diagnostic issues. Numerous reproductions of CT, MRI, US scans illustrate the aspects discussed. (orig./CB)

2001-09-01

317

Application of probabilistic methods to validate NPP pipewhip impact simulations  

Energy Technology Data Exchange (ETDEWEB)

Piping in nuclear power plants is vital to the proper operation and safety of these facilities. To assure safety in the unlikely event of a pipe break, it is necessary to evaluate the consequences from the resulting whipping pipe on neighboring components and structures. Numerical simulations allow for rapid evaluation of these consequences. Before simulations can be accepted, however, the methodology and computer codes must be validated against experimental results. This paper uses a probabilistic approach to validate pipe whip simulations against limited experimental results. Probabilistic analysis software was developed and coupled to existing deterministic finite element software. An example of a whipping pipe impacting against a reinforced concrete slab was simulated. The described probabilistic approach was used to validate the numerical simulations. The conclusions obtained were that the numerical simulations of ...

2006-02-15

318

Animal Models in Carotenoids Research and Lung Cancer Prevention1  

UK PubMed Central (United Kingdom)

Numerous epidemiological studies have consistently demonstrated that individuals who eat more fruits and vegetables (which are rich in carotenoids) and who have higher serum β-carotene levels...Full Text Available

319

Analysis of Protein Covalent Modification by Xenobiotics using a Covert Oxidatively Activated Tag  

UK PubMed Central (United Kingdom)

Numerous xenobiotics, including therapeutics agents, are substrates for bioactivation to electrophilic reactive intermediates that may covalently modify biomolecules. Selective estrogen receptor...Full Text Available

2005-09-01

320

Alcoholic Beverages and Prostate Cancer in a Prospective US Cohort Study  

UK PubMed Central (United Kingdom)

Despite numerous investigations, the correlation between alcohol consumption and prostate cancer risk remains uncertain. This report investigated the association between alcohol use and prostate cancer...Full Text Available

2010-10-01

321

Advanced MRI Methods for Assessment of Chronic Liver Disease  

UK PubMed Central (United Kingdom)

MRI plays an increasingly important role for assessment of patients with chronic liver disease. MRI has numerous advantages, including lack of ionizing radiation and the possibility of performing...Full Text Available

2009-07-01

322

Adult-born hippocampal neurons are more numerous, faster-maturing and more involved in behavior in rats than in mice  

UK PubMed Central (United Kingdom)

Neurons are born throughout adulthood in the hippocampus and show enhanced plasticity compared to mature neurons. However, there are conflicting reports on whether or not young neurons contribute...Full Text Available

2009-11-18

323

Acetylation of Histones and Transcription-Related Factors  

UK PubMed Central (United Kingdom)

The state of chromatin (the packaging of DNA in eukaryotes) has long been recognized to have major effects on levels of gene expression, and numerous chromatin-altering strategies—including...Full Text Available

2000-06-01

324

A non-radioactive dot-blot assay for transglutaminase activity  

UK PubMed Central (United Kingdom)

Aberrant transglutaminase (TG) activity has been implicated in the pathology of numerous diseases including Huntington disease and Alzheimer disease. To fully characterize the role of TGs in...Full Text Available

2009-07-01

325

Theoretical investigation of the behavior of an acoustic metamaterial with extreme Young's modulus  

British Library Electronic Table of Contents (United Kingdom)

A mechanical model with local resonators is proposed as an acoustic metamaterial that exhibits an unusual frequency-dependent effective stiffness. If treated as an equivalent elastic solid, its effective Young's modulus can become unbounded or vanishingly small at two respective frequencies. Moreover, in a certain frequency range, the effective Young's modulus would become negative, resulting in a band gap that coincides with this frequency range. The wave attenuation behavior and mechanism are studied through numerical simulations on the acoustic metamaterial model. The capability of the metamaterial to selectively block or filter unwanted waves is demonstrated by a numerical simulation example.

2011-01-01

326

The use of a mesoscale numerical model for evaluations of pollutant transport and diffusion in coastal regions and over irregular terrain  

Energy Technology Data Exchange (ETDEWEB)

A modelling approach is presented that appears to have the potential to provide reliable assessments of pollution concentration in coastal zones and complex terrain, where the assumptions behind current operational air quality models often are inadequate. With the use of a numerical mesoscale model (NMM), physically consistent flow fields can be predicted, thereby providing higher spatial and temporal resolution in the meteorological fields than would be available from a limited number of observation points. These predictions are used to calculate mean trajectories of pollutant parcels, as well as to provide quantitative estimates of pollution concentration using two techniques.

1983-03-01

327

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

Energy Technology Data Exchange (ETDEWEB)

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

328

Solution of vector Stefan problems with cross-diffusion  

Science.gov (United States)

A general model for the dissolution of particles in multi-component alloys is proposed and analyzed. The model is based on diffusion equations with cross-terms for the several species, combined with a Stefan condition as the equation of motion of the interface between the particle and diffusive phase. Several numerical schemes for the solution of the Stefan problem are proposed and compared. It turns out that diagonalization is useful for numerical purposes. However, for the case of position-dependent diffusion coefficients one has to use a different scheme. Here, we analyze stability and workload of several time integration methods.

2005-04-01

329

Simulation of concrete perforation based on a continuum damage model  

Energy Technology Data Exchange (ETDEWEB)

Numerical simulation of dynamic fracture of concrete slabs, impacted by steel projectiles, was carried out in this study. The concrete response was described by a continuum damage model. This continuum damage model was originally developed to study rock fragmentation and was modified in the present study with an emphasis on the post-limit structural response. The model was implemented into a transient dynamic explicit finite element code LS-DYNA2D and the code was then used for the numerical simulations. The specific impact configuration of this study follows the experiment series conducted by Hanchak et al. Comparisons between calculated results and measured data were made. Good agreements were found.

1994-10-01

330

Relaxation oscillations and diffusion chaos in the Belousov reaction  

British Library Electronic Table of Contents (United Kingdom)

Asymptotic and numerical analysis of relaxation self-oscillations in a three-dimensional system of Volterra ordinary differential equations that models the well-known Belousov reaction is carried out. A numerical study of the corresponding distributed model-the parabolic system obtained from the original system of ordinary differential equations with the diffusive terms taken into account subject to the zero Neumann boundary conditions at the endpoints of a finite interval is attempted. It is shown that, when the diffusion coefficients are proportionally decreased while the other parameters remain intact, the distributed model exhibits the diffusion chaos phenomenon; that is, chaotic attractors of arbitrarily high dimension emerge.

2011-01-01

331

Quasi-landau resonances: analytic treatment of the hydrogenic spectrum in the two-dimensional model and relation to other strong-field problems  

Energy Technology Data Exchange (ETDEWEB)

The two-dimensional WKB model has been the basis for several investigations of the quasi-Landau hydrogenic spectrum. Whereas other authors have used numerical integration, it is shown that the results can be obtained analytically in terms of elliptic integrals. The later are easily generated by even programmable pocket calculators, from which numerical results - which are in good agreement with experiments - are easily obtained. A further advantage of using elliptic integrals is that several strong-field problems can be shown to be special cases of a general potential whose energy and spacing are expressible in terms of them.

1982-11-01

332

Outer Tangency Bifurcations of Chaotic Sets  

Science.gov (United States)

We present and explain numerical results illustrating the mechanism of a type of discontinuous bifurcation of a chaotic set that occurs in typical dynamical systems. After the bifurcation, the chaotic set acquires new pieces located at a finite distance from its location just before the bifurcation, and these new pieces were not part of a previously existing chaotic set. A scaling law is given describing the creation of unstable periodic orbits following such a bifurcation. We also provide numerical evidence of such a bifurcation for a nonattracting chaotic set of the H{acute e}non map. {copyright} {ital 1998} {ital The American Physical Society}

1998-06-01

333

On the structure of locally Lipschitz minimax solutions of the Hamilton-Jacobi-Bellman equation in terms of classical characteristics  

British Library Electronic Table of Contents (United Kingdom)

Necessary and sufficient conditions for a minimax solution to the Cauchy problem for the Hamilton-Jacobi-Bellman equation are obtained as viability conditions for classical characteristics inside the graph of this solution. Using this property, a representative formula for a one-dimensional conservation law in terms of classical characteristics is derived. An estimate of the numerical integration of the characteristic system is presented and errors of numerical realizations of representative formulas are determined for the conservation law and its potential equal to the minimax solution of the Hamilton-Jacobi-Bellman equation.

2010-01-01

334

Numerical study of Cosmic Ray Diffusion in MHD turbulence  

CERN Document Server

We study diffusion of Cosmic Rays (CRs) in turbulent magnetic fields using test particle simulations. Electromagnetic fields are produced in direct numerical MHD simulations of turbulence and used as an input for particle tracing, particle feedback on turbulence being ignored. Statistical transport coefficients from the test particle runs are compared with earlier analytical predictions. We find qualitative correspondence between them in various aspects of CR diffusion. In the incompressible case, that we consider in this paper, the dominant scattering mechanism occurs to be the non-resonant mirror interactions with the slow-mode perturbations. Perpendicular transport roughly agrees with being produced by magnetic field wandering.

2010-01-01

335

Numerical simulation of internal reconnection event in spherical tokamak  

Energy Technology Data Exchange (ETDEWEB)

Three-dimensional magnetohydrodynamic simulations are executed in a full toroidal geometry to clarify the physical mechanisms of the Internal Reconnection Event (IRE), which is observed in the spherical tokamak experiments. The simulation results reproduce several main properties of IRE. Comparison between the numerical results and experimental observation indicates fairly good agreements regarding nonlinear behavior, such as appearance of localized helical distortion, appearance of characteristic conical shape in the pressure profile during thermal quench, and subsequent appearance of the m=2/n=1 type helical distortion of the torus. (author)

1999-07-01

336

Numerical methods for solving problems with a free boundary. Chislennye metody resheniia zadach so svobodnoi granitsei  

Energy Technology Data Exchange (ETDEWEB)

Approximate methods are presented for solving nonlinear boundary value problems with an unknown (free) boundary, such as the Stefan problem in heat conductivity. Examples of this kind of problems in thermal physics, hydrodynamics, elasticity, and plasma physics are examined. Attention is given to the principal computational methods for solving stationary problems for second- and fourth-order elliptic equations, such as the domain transformation and penalty methods. To illustrate the capabilities of the methods presented here, examples of numerical solutions are presented for various specific applied problems. 255 references.

1987-01-01

337

Numerical Computation of Diffusion on a Surface  

Energy Technology Data Exchange (ETDEWEB)

We present a numerical method for computing diffusive transport on a surface derived from image data. Our underlying discretization method uses a Cartesian grid embedded boundary method for computing the volume transport in region consisting of all points a small distance from the surface. We obtain a representation of this region from image data using a front propagation computation based on level set methods for solving the Hamilton-Jacobi and eikonal equations. We demonstrate that the method is second-order accurate in space and time, and is capable of computing solutions on complex surface geometries obtained from image data of cells.

2005-02-24

338

Nonlinear dynamics of heat transfer enhancement using eddy promoters  

Science.gov (United States)

This investigation concerns the nonlinear dynamics of heat transfer from a surface using an upstream eddy promoter. A numerical model is developed for the coupled fluid flow and heat transfer process based on a modified MacCormack scheme. Numerical simulations are carried out to determine the response and heat transfer enhancement due to the promoter. The average heat transfer from a cavity floor is seen to be increased by a factor of approximately five over the unpromoted'' flow. Another interesting feature of the study is the nonlinear viscous flow dynamics from the cylinder-wall interaction which differ significantly from the familiar cylinder-free stream patterns.

1994-02-01

339

Nonlinear dynamics of heat transfer enhancement using eddy promoters  

Energy Technology Data Exchange (ETDEWEB)

This investigation concerns the nonlinear dynamics of heat transfer from a surface using an upstream eddy promoter. A numerical model is developed for the coupled fluid flow and heat transfer process based on a modified MacCormack scheme. Numerical simulations are carried out to determine the response and heat transfer enhancement due to the promoter. The average heat transfer from a cavity floor is seen to be increased by a factor of approximately five over the unpromoted'' flow. Another interesting feature of the study is the nonlinear viscous flow dynamics from the cylinder-wall interaction which differ significantly from the familiar cylinder-free stream patterns.

1994-02-01

340

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

International Nuclear Information System (INIS)

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

341

Heating of magneto-rheological fluid dampers: a theoretical study  

Science.gov (United States)

This paper focuses on a theoretical model that predicts the temperature increase of Magneto-rheological (MR) fluid dampers experiencing a sinusoidal input motion. A theoretical model is developed to estimate the temperature rise based on the non-linear behavior of the MR fluid damper. This model is solved numerically, and the numerical solution is compared with a known linear solution and experimental result in order to validate the accuracy of the model. Also, a non-dimensional form of the governing equations are developed to examine the key parameters. The non-dimensional terms show the effect of external and internal parameters on the trends of heat dissipation as well as heat generation within the MR fluid damper.

1999-05-01

342

Heat transfer characteristics of laminar flow in internally finned tubes under various boundary conditions  

Science.gov (United States)

Numerical solutions for fully developed laminar flow in internally finned tubes with trapezoidal and triangular fin profiles were given with Finite Element Method (FEM): The heat transfer characteristics were obtained and compared under the boundary conditions of uniform heat flux, uniform wall temperature, and the third boundary condition with finite wall thermal conductivity considered. The numerical results show that boundary conditions have pronounced effects on the temperature field. Furthermore, a new mechanism on the heat transfer augmentation of internally finned tubes is proposed.

1994-06-01

343

Formation of charge and energy distribution of heavy ions in substance according to diffusion model  

International Nuclear Information System (INIS)

The formation of the ions charge and energy distributions of the ions slowed down or randomly changing their charge in the collisions with the medium particles are studied. The effect of the ions dispersion by the charge on the Bragg curve form is investigated. The proposed diffusion approximation for the heavy ions kinetic equation makes it possible to determine simply the parameters of the ions distribution by charge and energy on the whole way of the ions motion. The relation between the ions charge distribution characteristics and the cross sections of the ionization-recombination processes is indicated. The ions distributions, calculated in the proposed analytical model, are compared with the results of the numerical calculations. Good agreement between the analytical, numerical and experimental results is obtained

2003-11-01

344

Feynman integral calculus  

Energy Technology Data Exchange (ETDEWEB)

The goal of the book is to summarize those methods for evaluating Feynman integrals that have been developed over a span of more than fifty years. The book characterizes the most powerful methods and illustrates them with numerous examples starting from very simple ones and progressing to nontrivial examples. The book demonstrates how to choose adequate methods and combine evaluation methods in a non-trivial way. The most powerful methods are characterized and then illustrated through numerous examples. This is an updated textbook version of the previous book (Evaluating Feynman integrals, STMP 211) of the author. (orig.)

2006-07-01

345

Exploring the structure of the proton through polarization observables in l p \\to jet X  

CERN Document Server

We present results for a complete set of polarization observables for jet production in lepton proton collision, where the final state lepton is not observed. The calculations are carried out in collinear factorization at the level of Born diagrams. For all the observables we also provide numerical estimates for typical kinematics of a potential future Electron Ion Collider. On the basis of this numerical study, the prospects for the transverse single target spin asymmetry are particularly promising. This observable is given by a certain quark-gluon correlation function, which has a direct relation to the transverse momentum dependent Sivers parton distribution.

2011-01-01

346

Estimation of static formation temperatures in geothermal wells  

Energy Technology Data Exchange (ETDEWEB)

Stabilized formation temperatures were estimated at different depths in 40 wells from the Los Humeros geothermal field, Mexico, using the Horner and the spherical radial flow (SRF) methods. The results showed that the Horner method underestimates formation temperatures, while the SRF method gives temperatures that are closer to the true formation temperatures. This was supported by numerical simulation of a combined circulation and shut-in period in several wells, and results for well H-26 are presented. Numerical reproduction of logged temperature is more feasible if an initial temperature profile based on the SRF method is employed instead of using an initial temperature profile based on the Horner method. (Author)

2003-05-01

347

Development of three-dimensional aiming point guidance law  

British Library Electronic Table of Contents (United Kingdom)

A new aiming point guidance (APG) law in 3-dimensional space is derived analytically. The guidance law is capable of guiding the missile (interceptor) to a straight collision course with respect to the target. The missile turning rate command proportional to the error angle between the current missile heading and the predicted aim point is calculated based on the predicted target position. Performance of the APG law is numerically evaluated and compared with the proportional navigation guidance (PNG) law. The result of numerical simulation shows that the APG law is superior to the PNG law in terms of miss distance, time of interception and final stage missile turning rate demand.

2010-01-01

348

Determination of the Venezuelan coastal-zone wind atlas by using numerical methods  

Energy Technology Data Exchange (ETDEWEB)

This work deals with the development of wind maps in the Venezuelan coastal zones (South America). The Navier-Stokes equations for real viscous incompressible flow are discretized via the finite element method and they are applied to a full 3D numerical model. Two regions were analyzed: the Margarita island and the Paraguana peninsula, both of them located in the Caribbean Sea at the North of Venezuela. These regions were modeled by using a three dimensional control volume, discretized through hexaedric eight-noded finite elements. Some wind maps obtained in this research are presented and discussed. (author)

1995-12-31

349

Determination of Scaling Parameter and Dynamical Resonances in Complex-Rotated Hamiltonian II: Numerical Analysis  

International Nuclear Information System (INIS)

This paper is concerned with the determination of a unique scaling parameter in complex scaling analysis and with accurate calculation of dynamics resonances. In the preceding paper we have presented a theoretical analysis and provided a formalism for dynamical resonance calculations. In this paper we present accurate numerical results for two non-trivial dynamical processes, namely, models of diatomic molecular predissociation and of barrier potential scattering for resonances. The results presented in this paper confirm our theoretical analysis, remove a theoretical ambiguity on determination of the complex scaling parameter, and provide an improved understanding for dynamical resonance calculations in rigged Hilbert space.

2008-03-15

350

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

International Nuclear Information System (INIS)

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

351

Adiabatic Rormation of a Matched-beam Distribution for an Alternating-gradient Quadrupole Lattice  

Energy Technology Data Exchange (ETDEWEB)

The formation of a quasiequilibrium beam distribution matched to an alternating-gradient quadrupole focusing lattice by means of the adiabatic turn-on of the oscillating focusing field is studied numerically using particle-in-cell simulations. Quiescent beam propagation over several hundred lattice periods is demonstrated for a broad range of beam intensities and vacuum phase advances describing the strength of the oscillating focusing field. Properties of the matched-beam distribution are investigated. In particular, self-similar evolution of the beam density profile is observed over a wide range of system parameters. The numerical simulations are performed using the WARP particle-in-cell code.

2010-02-02

352

A method for resummation of perturbative series based on the stochastic solution of Schwinger-Dyson equations  

CERN Document Server

We propose a numerical method for resummation of perturbative series, which is based on the stochastic perturbative solution of Schwinger-Dyson equations. The method stochastically estimates the coefficients of perturbative series, and incorporates Borel resummation in a natural way. Similarly to the "worm" algorithm, the method samples open Feynman diagrams, but with an arbitrary number of external legs. As a test of our numerical algorithm, we study the scale dependence of the renormalized coupling constant in a theory of one-component scalar field with quartic interaction. We confirm the triviality of this theory in four and five space-time dimensions, and the instability of the trivial fixed point in three dimensions.

2011-01-01

353

Using support vector machines in the multivariate state estimation technique  

Energy Technology Data Exchange (ETDEWEB)

One approach to validate nuclear power plant (NPP) signals makes use of pattern recognition techniques. This approach often assumes that there is a set of signal prototypes that are continuously compared with the actual sensor signals. These signal prototypes are often computed based on empirical models with little or no knowledge about physical processes. A common problem of all data-based models is their limited ability to make predictions on the basis of available training data. Another problem is related to suboptimal training algorithms. Both of these potential shortcomings with conventional approaches to signal validation and sensor operability validation are successfully resolved by adopting a recently proposed learning paradigm called the support vector machine (SVM). The work presented here is a novel application of SVM for data-based modeling of system state variables in an NPP, integrated with a nonlinear, nonparametric technique called the multivariate ...

1999-07-01

354

Uncommon mucosal metastases to the stomach  

Science.gov (United States)

BackgroundMetastases to the stomach from an extra-gastric neoplasm are an unusual event, identified in less than 2% of cancer patients at autopsy. The stomach may be involved by hematogenous spread from a distant primary (most commonly breast, melanoma or lung), or by contiguous spread from an adjacent malignancy, such as the pancreas, esophagus and gallbladder. These latter sites may also involve the stomach via lymphatic or haematogenous spread. We present three cases of secondary gastric malignancy.Methods/ResultsThe first is a 19-year-old male who received a diagnosis of testicular choriocarcinoma in September 2004. Metastatic malignancy was demonstrated in the stomach after partial gastrectomy was performed to control gastric hemorrhage.The second is a 75-year-old male, generally well, who was diagnosed with adenocarcinoma of the lung in September 2005. Poorly differentiated adenocarcinoma of the lung was demonstrated in a subsequent biopsy of "gastric polyps".The third is an ...

2009-08-03

355

The SysMES framework: System management for networked embedded systems and clusters  

Energy Technology Data Exchange (ETDEWEB)

The ALICE heavy-ion particle physics experiment is currently being built at CERN near Geneva. It will use a PC cluster of 900 dual-processor machines for the last stages of the data readout process and a network of 400 microcomputers for the configuration and control of the cluster nodes. One of the most important objectives to be achieved in such experiments is to guarantee the utilized devices are running correctly during the experiment life-time. A second aspect is the extremely high availability and reliability requirements of the applications being run, the so called high level trigger (HLT). The SysMES framework is a scalable, decentralized, fault tolerant, dynamic, rule based tool set for the monitoring of networks of target systems and applications. The management algorithms consist of the following steps: system and application monitoring, recognition of undesirable states, event (message) generation, local event handling on the target, event forwarding to ...

2008-07-01

356

Synchrotron PES and NEXAFS studies of self-assembled aromatic thiol monolayers on Au(1 1 1)  

Energy Technology Data Exchange (ETDEWEB)

Self-assembled monolayers (SAMs) on various metal, semiconductor or insulator substrates can be easily modified with specific functional groups of interest and have promising applications in surface wetting (hydrophobic/hydrophilic modification), tribology, corrosion protection, sensor electrodes modification, molecular and biomolecular recognition, protein adsorption, cell adhesion, and molecular- or organic-electronic device fabrications. In this paper, we highlight recent progress in the development of SAMs on solid substrates as well as their practical applications, with particular emphasis on the characterization of self-assembled aromatic thiol monolayers with different functional groups on Au(1 1 1) using synchrotron-based photoemission spectroscopy and near-edge X-ray absorption fine structure measurements. The SAM-related molecular orientation, electronic structures, and chemical bonding are presented. Using copper(II) phthalocyanine as a model system, we ...

2009-05-15

357

Studies on sugar recognizing and binding protein (lectin) in marine invertebrates (physiological control of lectin); Kaiyo musekitsui dobutsu no toninshiki ketsugo tanpakushitsu (lectin) ni kansuru kenkyu (lectin no seiriteki seigyo)  

Energy Technology Data Exchange (ETDEWEB)

Lectin is a generic name of sugar binding protein in living organisms. With an objective to clarify physiological functions of lectin in marine invertebrates and utilize it as a useful material in the bio-chemical industry, studies were carried out on the chemical structure, distribution in living organisms and structural changes of lectin. Lectin is involved with such physiological actions as immunity reactions, generation and differentiation, Ca fixation and symbiosis. Lectin is one of the main components of lymph fluid in shellfish and crustacean, and is a multi-functional polymer that is related with foreign substance recognition, Ca transport, and shell formation. Lectin of a certain kind shows strong actions to accelerate cell division. Organs and cells were cultivated for lectin producing organs and lectin producing cells to verify the production thereof. Elucidation was attempted in a molecular level on such physiological functions as foreign substance ...

1993-03-01

358

Studies of the applicability of opto-electronic devices for instrumentation in high-energy physics. Progress report, June 1, 1981-May 31, 1982  

Energy Technology Data Exchange (ETDEWEB)

Instrumentation research to study the feasibility of using optical data processing techniques to solve real-time pattern recognition problems for high energy physics experiments is now in its second year. During the past year, a prototype optical processor for use in BNL Experiment 702 was conceived and designed, using test data from the experiment and simulating the optical processor in the computer. A number of technical studies have been made, mostly relating to the selection of the optical filter for the processor. Comparisons between natural and synthetic holograms, both bleached and unbleached, have been made. We conclude from these tests that the kinoform, a computer-generated phase hologram, is the optimal choice for this processor. A new method for producing the kinoform has been tried by this group with encouraging results. The optical design for the prototype processor is complete, and the required optical elements, sources, and the detector have all ...

1982-01-01

359

Recognition and Detoxification of the Insecticide DDT by Drosophila melanogaster Glutathione S-Transferase D1  

Energy Technology Data Exchange (ETDEWEB)

GSTD1 is one of several insect glutathione S-transferases capable of metabolizing the insecticide DDT. Here we use crystallography and NMR to elucidate the binding of DDT and glutathione to GSTD1. The crystal structure of Drosophila melanogaster GSTD1 has been determined to 1.1 {angstrom} resolution, which reveals that the enzyme adopts the canonical GST fold but with a partially occluded active site caused by the packing of a C-terminal helix against one wall of the binding site for substrates. This helix would need to unwind or be displaced to enable catalysis. When the C-terminal helix is removed from the model of the crystal structure, DDT can be computationally docked into the active site in an orientation favoring catalysis. Two-dimensional {sup 1}H,{sup 15}N heteronuclear single-quantum coherence NMR experiments of GSTD1 indicate that conformational changes occur upon glutathione and DDT binding and the residues that broaden upon DDT binding support the predicted binding site. ...

2010-06-14

360

Reading Intervention Outcomes for Adults with Disabilities in a Vocational Rehabilitation Setting: Results of a 3-Year Research and Demonstration Grant  

Science.gov (United States)

This study reports on an examination of the effectiveness of a reading intervention for adults with disabilities in a vocational rehabilitation setting. Participants were 57 adults with disabilities and low reading skills enrolled at the Reading Clinic at the Michigan Career and Technical Institute. As part of a 3-year research and demonstration grant evaluation project, participants received an individualized reading intervention that targeted phonological processing, orthographic pattern recognition, and comprehension for adults with disabilities and low reading levels. The particular program incorporated fluency exercises at every level of the structured, explicit, and systematic intervention curriculum. Results showed that participants made moderate to large gains in passage reading accuracy and comprehension during the course of the intervention. Gains in passage reading rate were not statistically significant. Results are discussed in relation to theories of ...

2011-07-01

361

Raman and SERS recognition of ?-carotene and haemoglobin fingerprints in human whole blood.  

Science.gov (United States)

The present work reports on Raman and Surface Enhanced Raman Scattering (SERS) vibrational fingerprints of ?-carotene and haemoglobin in fresh whole blood (i.e. right after blood test) with different laser excitations, i.e. visible (514 nm) and near-infrared (NIR, 785 nm). The use of colloidal silver nanoparticles significantly increases the Raman signal, thus providing a clear SERS spectrum of blood. The collected spectra have been examined and marker bands of ?-carotene and of the haem prosthetic group of haemoglobin have been found. In particular, the fundamental features of ?-carotene (514 nm excitation), blood proteins and haem molecules (785 nm excitation) were recognized and assigned. Moreover haemoglobin SERS signals can be identified and related with its oxygenation state (oxy-haemoglobin). The data reported show the prospects of Raman and SERS techniques to detect important bio-molecules in a whole blood sample with no pre-treatment. PMID:21622021

2011-03-26

362

Primary gonadal damage following treatment of brain tumors in childhood  

Energy Technology Data Exchange (ETDEWEB)

Gonadal function was studied in two groups of children previously treated for medulloblastoma with surgery followed by postoperative craniospinal irradiation. In group 1 but not in group 2, the children also received adjuvant chemotherapy for one to two years. All children in group 1 received a nitrosourea (BCNU or CCNU), plus vincristine in four and procarbazine in three patients. The nine children in group 1 showed clinical and biochemical evidence of gonadal damage with elevated serum FSH concentrations and, in the boys, small testes for their stage of pubertal development. In group 2 (n . 8), each child had completed pubertal development normally, the boys had adult sized testes and the girls regular menses. Gonadotropin values were normal in all eight children. We conclude that nitrosoureas were responsible for the gonadal damage in the children in group 1, with procarbazine also contributing to the damage in the three children who received this drug. In view of the limited proved ...

1983-10-01

363

Opportunities for petroleum company leadership in host nations sustainable petroleum economic development business  

Energy Technology Data Exchange (ETDEWEB)

This paper examines the dynamic international political economic environment in which petroleum exploration and production companies must operate when considering investments in the economically transitional nations of the former Soviet Union or developing nations In this period of critical global changes low oil prices is only one factor with which petroleum companies Must be. concerned in their investment decisions Other factors include the transition from a bipolar world to a multipolar world of free trade zones. the general malaise of the international economy public and political recognition that nations and industries can no longer practice environmental {open_quotes}beggar-thy-neighbor{close_quotes} policies, and the rejection of aggregate national economic growth policies for sustainable economic development policies in both the Developed and developing world This paper focuses on actions which investing petroleum exploration and production companies can ...

1995-12-31

364

Open charm effects in $e^+e^-\\to J/\\psi \\eta$, $J/\\psi \\pi^0$ and $\\phi\\eta_c$  

CERN Document Server

We propose to study the open charm effects in $e^+ e^-\\to J/\\psi\\eta$, $J/\\psi\\pi^0$ and $\\phi\\eta_c$. We show that the exclusive cross section lineshapes of these processes would be strongly affected by the open charm effects. Since the final state light meson productions are through soft gluon radiations, we assume a recognition of this soft process via charmed meson loops at hadronic level. A unique feature among these three reactions is that the $D\\bar{D^*}+c.c.$ open channel is located in a relatively isolated energy, i.e. $\\sim 3.876$ GeV, which is sufficiently far away from the known charmonia $\\psi(3770)$ and $\\psi(4040)$. Therefore, the cross section lineshapes of these reactions may provide an opportunity for singling out the open charm effects with relatively well-defined charmonium contributions. In particular, we find that reaction $e^+ e^-\\to J/\\psi\\pi^0$ is sensitive to the open charm $D\\bar{D^*}+c.c.$ Due to the dominance of the ...

2011-01-01

365

On Geometrical Interpretation of Non-Abelian Flat Direction Constraints  

CERN Document Server

In order to produce a low energy effective field theory from a string model, it is necessary to specify a vacuum state. In order that this vacuum be supersymmetric, it is well known that all field expectation values must be along so-called flat directions, leaving the F- and D-terms of the scalar potential to be zero. The situation becomes particularly interesting when one attempts to realize such directions while assigning VEVS to fields transforming under non-Abelian representations of the gauge group. Since the expectation value is now shared among multiple components of a field, satisfaction of flatness becomes an inherently geometrical problem in the group space. Furthermore, the possibility emerges that a single seemingly dangerous F-term might experience a self-cancellation among its components. The hope exists that the geometric language can provide an intuitive and immediate recognition of when the D and F conditions are simultaneously compatible, as well ...

2005-01-01

366

Nuclear mass prediction as an image reconstruction problem: can observed pattern determine mass values?  

Energy Technology Data Exchange (ETDEWEB)

Theoretical prediction of nuclear masses is analyzed as a pattern recognition problem on the N-Z plane. A global pattern is observed by plotting the differences between measured masses and Liquid Drop Model (LDM) predictions. After unfolding the data by removing the smooth LDM mass contributions, the remaining microscopic effects have proved difficult to model, although they display a striking pattern. These deviations carry information related to shell closures, nuc]ear deformation and the residual nuclear interactions. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. We show here that employing a Fourier transform deconvolution method these by masses can be predicted with similar accuracy than standard methods. We believe that a more general approach needs to be ...

2006-07-01

367

Nuclear mass prediction as an image reconstruction problem: can observed pattern determine mass values?  

International Nuclear Information System (INIS)

Theoretical prediction of nuclear masses is analyzed as a pattern recognition problem on the N-Z plane. A global pattern is observed by plotting the differences between measured masses and Liquid Drop Model (LDM) predictions. After unfolding the data by removing the smooth LDM mass contributions, the remaining microscopic effects have proved difficult to model, although they display a striking pattern. These deviations carry information related to shell closures, nuc]ear deformation and the residual nuclear interactions. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. We show here that employing a Fourier transform deconvolution method these by masses can be predicted with similar accuracy than standard methods. We believe that a more general approach needs to be ...

368

Machine vision  

Energy Technology Data Exchange (ETDEWEB)

To keep up with the speeds of modern production lines, most machine vision applications require very powerful computers (often parallel-processing machines), which process millions of points of data in real time. The human brain performs approximately 100 billion logical floating-point operations each second. That is 400 times the speed of a Cray-1 supercomputer. The right software must be developed for parallel-processing computers. The NSF has awarded Rensselaer Polytechnic Institute (Troy, N.Y.) a $2 million grant for parallel- and image-processing software research. Over the last 15 years, Rensselaer has been conducting image-processing research, including work with high-definition TV (HDTV) and image coding and understanding. A similar NSF grant has been awarded to Michigan State University (East Lansing, Mich.) Neural networks are supposed to emulate human learning patterns. These networks and their hardware implementations (neurocomputers) show a great deal of promise for ...

1989-06-01

369

High-resolution sequence stratigraphy of a Hettangian-Sinemurian parallic succession, Bornholm, Denmark  

Energy Technology Data Exchange (ETDEWEB)

Sequence stratigraphic interpretation of paralic successions is complicated by the complex interfingering of marine and continental strata. The successions may also include terrestrial extensions of marine parasequences and completely independent lacustrine parasequence analogues. Failure in recognizing the possible interbedding of these two independent parasequence types may lead to construction of sequence stratigraphic schemes based on incompatible data sets. We have studied a Lower Jurassic paralic section from the Baltic island of Bornholm. The Hettangian-Sinemurian Sose Bugt Member (Ronne Formation) of Bornholm includes lacustrine, fluvial and restricted marine, estuarine deposits reflecting the basin-margin position. Biostatigraphic resolution is poor and a sequence stratigraphic interpretation of the paralic succession is far from straightforward. A multidisciplinary approach including facies analysis, recognition and lateral tracting of key surface, ...

1995-04-01

370

Growth of tailored sillenite photorefractives for optical correlation  

Science.gov (United States)

Photorefractives, in general, are among the most promising materials solutions to real time optical correlation. Applications include military target recognition and civilian robotic vision. Crystals of sillenite structure photorefractives, Bi12XO20, where X equals Si, Ge, or Ti, have been grown by melt techniques and in the case of bismuth silicon oxide (BSO) and bismuth titanium oxide (BTO) by the hydrothermal method of high-temperature/high-pressure solution growth. The two growth methods are discussed and crystals grown by the two methods are compared in this paper. Optical absorption and TSC studies show that hydrothermal BSO is essentially free of the native antisite Bi defect which usually acts as a donor. These studies also show that the trap density is greatly reduced in hydrothermal material. Preliminary experiments show that hydrothermal BTO crystals have improved properties over melt grown samples. Al and P act as donors and acceptors respectively and ...

1995-06-01

371

Fuzzy logic of Aristotelian forms  

Energy Technology Data Exchange (ETDEWEB)

Model-based approaches to pattern recognition and machine vision have been proposed to overcome the exorbitant training requirements of earlier computational paradigms. However, uncertainties in data were found to lead to a combinatorial explosion of the computational complexity. This issue is related here to the roles of a priori knowledge vs. adaptive learning. What is the a-priori knowledge representation that supports learning? I introduce Modeling Field Theory (MFT), a model-based neural network whose adaptive learning is based on a priori models. These models combine deterministic, fuzzy, and statistical aspects to account for a priori knowledge, its fuzzy nature, and data uncertainties. In the process of learning, a priori fuzzy concepts converge to crisp or probabilistic concepts. The MFT is a convergent dynamical system of only linear computational complexity. Fuzzy logic turns out to be essential for reducing the combinatorial complexity to linear one. I ...

1996-12-31

372

Fuzzy decision making in multiobjective long-term scheduling of hydrothermal system  

Energy Technology Data Exchange (ETDEWEB)

In the paper, a fuzzy decision-making methodology is presented to decide the generation schedule of long-term hydrothermal problems with explicit recognition of statistical uncertainties in system production cost data, NO{sub x} emission data, system load demand and hydro reservoir water inflows. In deciding the optimal operation, three objectives operating cost, NO{sub x} emission and unsatisfied load demand over the whole of the planning period are simultaneously minimised. Specific technique is put forth to convert the stochastic models into their deterministic equivalents. The weighted minimax method is used to simulate the tradeoff relation between the conflicting objectives in the non-inferior domain. The fuzzy set theory is exploited to choose the best operating point over the tradeoff curve. An efficient decomposition technique is applied to reduce the complexity of the problem. In each subproblem, thermal generations are obtained by using simplified method ...

2001-01-01

373

Functional expression of anti-hepatitis B virus (HBV) preS2 antigen scFv by cspA promoter system in Escherichia coli and application as a recognition molecule for single-walled carbon nanotube (SWNT) field effect transistor (FET)  

British Library Electronic Table of Contents (United Kingdom)

The preS2 antigens of hepatitis B virus (HBV), which causes a serious health problem in the world, have been implicated in hepatocyte cell binding and viral penetration. Therefore, the importance of antibody production against preS2 antigen for early diagnosis of HBV has been well established. In this study, the recombinant HBV preS2 single chain variable fragment (scFv) antibody was successfully expressed in E. coli with the novel cold shock vector (pCold) under the cspA promoter, and its expression level was compared with the pET vector under the T7 promoter. Additionally, a host with an oxidizing cytoplasm, E. coli trxB/gor double mutant, was used to improve the soluble expression. The anti-HBV preS2 scFv using pCold vector was successfully expressed in a soluble and functional form in ...

2010-01-01

374

Fluorescence based molecular in vivo imaging; Fluoreszenzgestuetzte molekulare Bildgebung in vivo  

Energy Technology Data Exchange (ETDEWEB)

Molecular imaging represents a modern research area that allows the in vivo study of molecular biological process kinetics using appropriate probes and visualization methods. This methodology may be defined- apart from the contrast media injection - as non-abrasive. In order to reach an in vivo molecular process imaging as accurate as possible the effects of the used probes on the biological should not be too large. The contrast media as important part of the molecular imaging can significantly contribute to the understanding of molecular processes and to the development of tailored diagnostics and therapy. Since more than 15 years PTB is developing optic imaging systems that may be used for fluorescence based visualization of tissue phantoms, small animal models and the localization of tumors and their predecessors, and for the early recognition of inflammatory processes in clinical trials. Cellular changes occur during many diseases, thus the molecular imaging ...

2008-12-15

375

Finding Dense Clusters via "Low Rank + Sparse" Decomposition  

CERN Document Server

Finding "densely connected clusters" in a graph is in general an important and well studied problem in the literature \\cite{Schaeffer}. It has various applications in pattern recognition, social networking and data mining \\cite{Duda,Mishra}. Recently, Ames and Vavasis have suggested a novel method for finding cliques in a graph by using convex optimization over the adjacency matrix of the graph \\cite{Ames, Ames2}. Also, there has been recent advances in decomposing a given matrix into its "low rank" and "sparse" components \\cite{Candes, Chandra}. In this paper, inspired by these results, we view "densely connected clusters" as imperfect cliques, where imperfections correspond missing edges, which are relatively sparse. We analyze the problem in a probabilistic setting and aim to detect disjointly planted clusters. Our main result basically suggests that, one can find \\emph{dense} clusters in a graph, as long as the clusters are sufficiently large. We conclude ...

2011-01-01

376

Effect of alcohols and temperature on the direct chiral resolutions of fipronil, isocarbophos and carfentrazone-ethyl.  

Science.gov (United States)

The enantiomeric separations of three pesticides fipronil (asymmetric nitrogen), isocarbophos (asymmetric phosphorus) and carfentrazone-ethyl (asymmetric carbon) were studied on cellulose-tri(3,5-dimethylphenylcarbamate) chiral stationary phase using high-performance liquid chromatography under normal phase. The mobile phase was n-hexane with alcohols including ethanol, n-propanol, iso-propanol, n-butanol and iso-butanol as polar modifiers. The flow rate was 1.0 mL/min with UV detection at 280, 225 and 230 nm for fipronil, isocarbophos and carfentrazone-ethyl respectively. The influence of the modifiers and their volume content and temperature from 0 to 50 degrees C on the separations was investigated. The chiral stationary phase showed excellent stereoselectivity for the two enantiomers of fipronil and isocarbophos and certain chiral recognition for carfentrazone-ethyl. Iso-propanol was more suitable for the chiral separation of isocarbophos and ...

2005-07-01

377

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants; Traitement des signaux de courants de Foucault pour le controle des tubes de generateurs de vapeur dans les centrales nucleaires REP  

Energy Technology Data Exchange (ETDEWEB)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostics system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1991-07-01

378

Eddy currents signal processing for steam generator inspection in PWR nuclear power plants. Traitement des signaux courants de Foucault pour le controle des tubes de generateurs de vapeur dans les centrales nucleaires REP  

Energy Technology Data Exchange (ETDEWEB)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostic system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

1992-01-01

379

Dynamic mass density and acoustic metamaterials  

Energy Technology Data Exchange (ETDEWEB)

Mass density of a composite is generally taken as the volume-averaged value of components' densities. Moreover, the same volume-averaged mass density is usually used to calculate the wave speed in the long-wavelength limit, i.e., where the wavelength is much larger than the size of the inhomogeneities. In this paper, we show via rigorous derivation that the dynamic mass density used in the calculation of (long-wavelength) wave speed can differ significantly from the static volume-averaged value. This recognition is shown to yield an excellent account of some recent experimental data, as well as to make possible the realization of acoustic metamaterials. Physical reason for the difference between two mass densities is attributed to the relative motion between the components. That is, the implicit assumption-that all components in a composite must move uniformly in the long-wavelength limit-can be violated in the limit of large acoustic impedance contrast ...

2007-05-15

380

Construction and Calibration of the Laser Alignment System for the CMS Tracker  

CERN Document Server

The CMS detector (Compact Muon Solenoid) is under construction at one of the four proton-proton interaction points of the LHC (Large Hadron Collider) at CERN, the European Organization for Nuclear Research (Geneva, Switzerland). The inner tracking system of the CMS experiment consisting of silicon detectors will have a diameter of 2.4 m and a length of 5.4 m representing the largest silicon tracker ever. About 15000 silicon strip modules create an active silicon area of 200 m2 to detect charged particles from proton collisions. They are placed on a rigid carbon fibre structure, providing stability within the working conditions of a 4 T solenoid magnetic field at ?10oC. Knowledge of the position of the silicon detectors at the level of 100 ?m is needed for an efficient pattern recognition of charged particle tracks. Metrology methods are used to survey tracker subdetectors and the integrated Laser Alignment System (LAS) provides absolute positioning of support ...

2006-01-01

381

Complications of gallstone disease: Mirizzi syndrome, cholecystocholedochal fistula, and gallstone ileus.  

Science.gov (United States)

Gallstone is a common disease with a 10% prevalence in the United States and Western Europe. However, it is only symptomatic in 20-30% of patients, with biliary pain "colic" being the most common symptom. Complications of asymptomatic gallstone disease are generally rare, with an incidence of <1 %/yr. The most common complications of gallstone disease are acute cholecystitis, acute pancreatitis, ascending cholangitis, and gangrenous gallbladder. Less frequent complications include Mirizzi syndrome, cholecystocholedochal fistula, and gallstone ileus. Mirizzi syndrome and cholecystocholedochal fistula are two manifestations of the same process that starts with impaction of a gallstone in the gallbladder neck that results in obstruction of the bile duct, causing jaundice. The gallstone may erode into the bile duct, causing cholecystocholedochal fistula. Gallstone ileus refers to small bowel obstruction resulting from the impaction of one or more gallstones after they have migrated ...

2002-02-01

382

Closed loop obstructions of the small bowel: role of Computed Tomography  

International Nuclear Information System (INIS)

Small bowel obstructions can be distinguished into more simple and closed loop obstructions. The latter is a more severe condition which is often complicated by strangulation with vascular impairment, edema and intramural and mesenteric hemorrhage. Consequent arterial insufficiency rapidly leads to ischemia, infarction and necrosis. The radiologist plays a role in the early recognition of the closed loop obstruction and of any sign of strangulation. The role of CT in the diagnosis and workup of patients with suspected intestinal occlusion has been analyzed in the literature with reported 63% sensitivity, 78% specificity and 66% accuracy. CT is also capable of revealing the causes of occlusion in 73-95% of cases. The above CT signs allow to identify closed loop obstruction and also small bowel strangulation, thus supplying a valuable contribution to diagnosis and accurate preoperative evaluation. The conclusion is that CT can accurately demonstrate the presence of ...

1999-01-01

383

Clinical-HINTS: integrated intelligent ICU patient monitoring and information management system.  

Science.gov (United States)

Clinical-HINTS (Health Intelligence System) is a horizontally integrated decision support system (DSS) designed to meet the requirements for intelligent real-time clinical information management in critical care medical environments and to lay the foundation for the development of the next generation of intelligent medical instrumentation. The system presented was developed to refine and complement the information yielded by clinical laboratory investigations, thereby benefiting the management of the intensive care unit (ICU) patient. More specifically, Clinical-HINTS was developed to provide computer-based assistance with the acquisition, organisation and display, storage and retrieval, communication and generation of real-time patient-specific clinical information in an ICU. Clinical-HINTS is an object-oriented system developed in C+2 to run under Microsoft Windows as an embryo intelligent agent. Current generic reasoning skills include perception and reactive cognition of patient ...

1997-01-01

384

Characterization of a novel missense mutation on murine Pax3 through ENU mutagenesis.  

Science.gov (United States)

N-ethyl-N-nitrosourea (ENU) mutagenesis has led to the elucidation of several regulator genes for melanocyte and skin development. Here we characterized a mutant from ENU mutagenesis with similar phenotype as that of Splotch mutant, including exencephaly, spina bifida and abnormal limbs in homozygotes as well as white belly spotting and occasionally loop-tail in heterozygotes. This novel mutant was named as Sp(xG). Through genome-wide linkage analysis in backcross progenies with microsatellite markers, the Sp(xG) was confined to a region between D1MIT415 and D1MIT7 on chromosome 1, where notable Pax3 gene was located. Direct sequencing revealed that Sp(xG) carried a nucleotide A894G missense transition in exon 6 of Pax3 gene that resulted in Asn to Asp substitution at amino acid 269 within the highly-conserved homeodomain (HD) DNA recognition module, which was the first point mutation found in this domain in mice. This N269D mutation impaired the transactivation ...

2011-07-19

385

Autism and the development of face processing.  

Science.gov (United States)

Autism is a pervasive developmental condition, characterized by impairments in non-verbal communication, social relationships and stereotypical patterns of behavior. A large body of evidence suggests that several aspects of face processing are impaired in autism, including anomalies in gaze processing, memory for facial identity and recognition of facial expressions of emotion. In search of neural markers of anomalous face processing in autism, much interest has focused on a network of brain regions that are implicated in social cognition and face processing. In this review, we will focus on three such regions, namely the STS for its role in processing gaze and facial movements, the FFA in face detection and identification and the amygdala in processing facial expressions of emotion. Much evidence suggests that a better understanding of the normal development of these specialized regions is essential for discovering the neural bases of face processing anomalies in ...

2006-10-01

386

Allosteric Tuning of the Intra-Cavity Binding Properties of a Calix[6]arene through External Binding to a ZnII Center Coordinated to Amino Side Chains  

British Library Electronic Table of Contents (United Kingdom)

Molecular recognition by calix[6]arene-based receptors bearing three primary alkylamino side chain arms (1) is described. Complexation of ZnII ion provides the dinuclear m-hydroxo complex ${{\\bf 2}{{{\\rm OH}\\hfill \\atop {\\rm G}\\hfill}}}$, XRD characterization of which, together with solution studies, provided evidence of its hosting of neutral polar organic guests G. Treatment of this complex with a carboxylic acid or a sulfonamide (XH) results in the formation of mononuclear species ${{\\bf 3}{{{\\rm X}\\hfill \\atop {\\rm G}\\hfill}}}$, one of which (X = Cl) has been characterized by XRD. A dicationic complex ${{\\bf 3}{{{\\rm RNH}{_{2}}\\hfill \\atop {\\rm G}\\hfill}}}$ is obtained upon treatment of ${{\\bf 2}{{{\\rm OH}\\hfill \\atop {\\rm G}\\hfill}}}$ with a mixture of an alkylamine and a strong acid....

2007-01-01

387

A novel approach to personal photo album representation and management  

Science.gov (United States)

In this paper we present a novel approach to personal photo album management allowing the end user to efficiently access the collection without any need for tedious manual annotation or indexing of the photos. The proposed work exploits methods and technology from the field of computer vision and pattern recognition for face detection, face representation and image annotation to automatically create description of images useful for content-based searching and retrieval. In fact, even if most of the used techniques are not reliable enough to address the general problem of content-based image retrieval, we show that, in a limited domain such as the one of personal photo album, it is possible to obtain results that improve the browsing capabilities of current photo album management systems. In particular, starting from the observation that most personal photos depict a usually small number of people in a relatively small number of different context (indoor, outdoor, ...

2008-01-01

388

Numerical study on the heat transfer to CO_2 flowing upward in a heated vertical tube at supercritical pressure  

International Nuclear Information System (INIS)

Full text of publication follows: As the coolant experiences no phase change in the core, SCWRs, unlike LWRs, cannot use design criteria based on the critical heat flux concept. The commonly accepted practice in SCWRs is to specify cladding temperature limits that must be met during transient and accident events. Therefore for the design of the SCWR, it is very important to predict the heat transfer coefficient to the supercritical water coolant with great accuracy. Our recent study focuses on the critical issue of measuring heat transfer to supercritical water at prototypical SCWR conditions and to develop the tools to predict the SCWR thermal behavior. A heat transfer test loop using a surrogate fluids, CO_2, is under construction. The reason of using CO_2 instead of water is that (i) valuable insight of the physical phenomena can be obtained with this fluid, and (ii) some existing facilities already used surrogate fluids, which in general have lower critical pressure and ...

2005-10-02

389

DECOVALEX II PROJECT. Technical report - Task 1A and 1B  

International Nuclear Information System (INIS)

DECOVALEX II project started in November 1995 as a continuation of the DECOVALEX I project, which was completed at the end of 1994. The project was initiated by recognizing the fact that a proper evaluation of the current capacities of numerical modelling of the coupled T-H-M processes in fractured media is needed not only for small scale, well controlled laboratory test cases such as those studied in DECOVALEX I, but also for less characterised, more complex and realistic in-situ experiments. This will contribute to validation and confidence building in the current mathematical models, numerical methods and computer codes. Four tasks were defined in the DECOVALEX II project: TASK 1 - numerical study of the RCF3 pumping test and shaft excavation at Sellafield by Nirex, UK; TASK 2 - numerical study of the in-situ T-H-M experiments at Kamaishi Mine by PNC, Japan; TASK 3 - review of current ...

390

Visualization of strong around motion calculated from the numerical simulation of Hyogo-ken Nanbu earthquake; Suchi simulation de miru Hyogoken nanbu jishin no kyoshindo  

Energy Technology Data Exchange (ETDEWEB)

Hyogo-ken Nanbu earthquake with a focus in the Akashi straits has given huge earthquake damages in and around Awaji Island and Kobe City in 1995. It is clear that the basement structure, which is steeply deepened at Kobe City from Rokko Mountains towards the coast, and the focus under this related closely to the local generation of strong ground motion. Generation process of the strong ground motion was discussed using 2D and 3D numerical simulation methods. The 3D pseudospectral method was used for the calculation. Space of 51.2km{times}25.6km{times}25.6km was selected for the calculation. This space was discretized with the lattice interval of 200m. Consequently, it was found that the basement structure with a steeply deepened basement, soft and weak geological structure thickly deposited on the basement, and earthquake faults running under the boundary of base rock and sediments related greatly to the generation of strong ground motion. ...

1996-10-01

391

Uncertainty estimation and global forecasting with a chemistry-transport model - application to the numerical simulation of air quality; Estimation de l'incertitude et prevision d'ensemble avec un modele de chimie transport - Application a la simulation numerique de la qualite de l'air  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is the evaluation of the quality of a chemistry-transport model, not by a classical comparison with observations, but by the estimation of its uncertainties due to the input data, to the model formulation and to the numerical approximations. The study of these 3 sources of uncertainty is carried out with Monte Carlo simulations, with multi-model simulations and with comparisons between numerical schemes, respectively. A high uncertainty is shown for ozone concentrations. To overcome the uncertainty-related limitations, a strategy consists in using the overall forecasting. By combining several models (up to 48) on the basis of past observations, forecasts can be significantly improved. This work has been also the occasion of developing an innovative modeling system, named Polyphemus. (J.S.)

2005-12-15

392

Time-dependent wavepacket calculations of molecular scattering from surfaces  

International Nuclear Information System (INIS)

An outline is given of time-dependent wavepacket methods as applied to calculations of molecular collisions with solid surfaces. The methods reviewed include numerical integration algorithms for the time-dependent Schroedinger equation, semiclassical wavepacket treatments, and approximations that treat some of the degrees-of-freedom quantum-mechanically and others classically. The computational and numerical characteristics of these methods are discussed, with emphasis on their particular advantages and relevance in the context of certain molecule/surface scattering problems. For the semiclassical and mixed quantal-classical treatments, the approximation errors and their physical origins are discussed. For the quantum wavepacket techniques a numerical error analysis is presented. The computational efficiency of the various algorithms is considered and examined in the context of several applications. The main focus is on ...

1986-01-01

393

The numerical simulation on low-level radioactive waste water, low-temperature cooling water drained effect of implement from the Daya Bay Nuclear Power Plant  

International Nuclear Information System (INIS)

In this paper, we calculated the radioactive concentration distribution of radioactive waste water, the temperature distribution of drained cooling water and the effect of implement from the Daya Bay Nuclear Power Plant on nearby waters range, discussed and analysed some problems of computational results and computation with Alternating Direction Implicit Method (ADI). The contents of the article included: the establishment of two-dimension tidal current equation, radioactive waste water pollutant dispersion equation and cooling water heat convection diffusion equation, the numerical difference calculation model of tidal current field, concentration field as well as temperature field, effect impingement with ADI method, numerical calculation results. The result of research showed that: when the Daya Bay Nuclear Power Plant is on normal operation and after the low level radioactive waste water and low temperature cooling water have been drained ...

394

Stability analysis of forced-flow cooled superconducting coil; Numerical simulation on multiple stability. Kyosei reikyaku gata chodendo coil no anteisei kaiseki; Taju anteisei no simulation  

Energy Technology Data Exchange (ETDEWEB)

The stability of a forced-flow cooled superconducting coil is investigated by use of the numerical simulation. The numerical code to integrate the simultaneous partial differential system composed of the 1 D hydrodynamic equations and the 1 D thermal conduction equation has been developed and stability margins are evaluated as functions of coolant mass flow rate, operation current and imposed magnetic field. The results of computations show that the stability margin is multi-valued with respect to these operation parameters, as expected from the experimental results. It is also shown that the appearance of the first unstable regime is closely related to the existance of the stagnant region located at the upstream side of the heated zone and that the second stable regime appears because the heat transfer is appreciably enhanced by the induced backflow due to the thermal expansion of coolant. 13 refs., 13 figs., 1 tab.

1990-06-25

395

Solid oxide fuel cell simulation and design optimization with numerical adjoint techniques  

Science.gov (United States)

This dissertation reports on the application of numerical optimization techniques as applied to fuel cell simulation and design. Due to the "multi-physics" inherent in a fuel cell, which results in a highly coupled and non-linear behavior, an experimental program to analyze and improve the performance of fuel cells is extremely difficult. This program applies new optimization techniques with computational methods from the field of aerospace engineering to the fuel cell design problem. After an overview of fuel cell history, importance, and classification, a mathematical model of solid oxide fuel cells (SOFC) is presented. The governing equations are discretized and solved with computational fluid dynamics (CFD) techniques including unstructured meshes, non-linear solution methods, numerical derivatives with complex variables, and sensitivity analysis with adjoint methods. Following the validation of the fuel cell model in 2-D and 3-D, the ...

2008-01-01

396

Post processing system for multi-dimensional thermal-hydraulic analyses  

International Nuclear Information System (INIS)

In the conventional visualization system for the computational results, only Japanese (Nihongo) Line Printer (NLP) was available to print two dimensional cross sectional plots of vector and scalar fields. To evaluate the phenomena, an analyst had to print many plots on the NLP. This task makes difficult to check the computational results immediately after the calculation. Recently, as the visualization tools, we introduced Micro AVS and Field View which are utilized widely in the scientific and the industrial fields. In order to show the numerical results on the visualization software, we constructed a post processing system which convert the results of the numerical code to 'intermediate files' which can be read by the visualization tools. As using this system, the examination of the numerical results can be executed on the display of the personal computer. Furthermore, the persuasive report and paper with high quality can ...

1999-01-01

397

Phenomenological 3D and 1D consistent models for shape-memory alloy materials  

Science.gov (United States)

The paper deals with the modeling and the development of a numerical procedure for the analysis of shape-memory alloy (SMA) elements in order to predict the main features of SMA devices. A 3D SMA model in the framework of small strain theory is developed starting from the thermo-mechanical model proposed by Souza et al. (Eur J Mech A/Solids 17:789-806, 1998) and modified by Auricchio and Petrini (Int J Numer Methods Eng 55:1255-1284, 2002). The aim of this paper is to propose some more modifications to the original model, to derive its consistent 1D formulation, to clarify the mechanical meaning of the material parameters governing the constitutive model. A robust time integration algorithm is developed in the framework of the finite element method and a new beam finite element is proposed. Some numerical applications and a comparison with experimental data available in literature are carried out in order to assess the ...

2009-08-01

398

Optimal scheduling of power systems with pumped hydropower storage plants adopting nonlinear programming techniques  

Energy Technology Data Exchange (ETDEWEB)

The paper is concerned with the economic operation of power systems comprising pumped storage and thermal plants. In power systems, pumped storage plants may receive the energy required for pumping water either from the system in which they are integrated or from a neighbouring system. Therefore, two mathematical formulations of the problem are presented depending on the source of energy during pumping. In both cases, the problem is reduced to a non linear optimization problem. Two numerical techniques are suggested for the solution of this optimization problem, namely the Lagrangian Multipliers technique and the Rosen Gradient Projection technique. Numerical examples are presented to demonstrate the techniques. Although the Lagrangian Multipliers technique has the advantage of being a well known technique, however, computer wise, the Rosen Gradient Projection technique proves to be more efficient. The results of the ...

1980-12-01

399

Numerical flow simulation in ship and ocean engineering; Senpaku kaiyo suiri bun`ta deno ryutai suchi simulation  

Energy Technology Data Exchange (ETDEWEB)

The improvement in the functions of the viscous flow calculation method VEGA-SHIP around a ship and the expansion of application range were described as the numerical flow simulation in ship and ocean engineering and at the same time application examples to the ocean engineering by the general-purpose flow simulation code FLOW-3D handling the non-steady flow with a free surface were introduced as the numerical simulation regarding such products as a water gate and a dam. In the VEGA-SHIP, water surface was handled as a fixed wall so that wave could not be calculated. Therefore, an algorithm for calculating wave on the water surface was added to the VEGA-SHIP and a calculation method simultaneously considering the creation of wave around the ship and viscosity was developed. The FLOW-3D was used to calculate the phenomenon where inside liquid moved greatly due to the oscillation of a tank and hit against and damaged the tank ceiling in the tank, ...

1995-01-01

400

Numerical Modeling of Magnesium Alloy Sheet Metal Forming at Elevated Temperature  

International Nuclear Information System (INIS)

The development of light-weight vehicle is in great demand for enhancement of fuel efficiency and dynamic performance. The vehicle weight can be reduced effectively by using lightweight materials such as magnesium alloys. However, the use of magnesium alloys in sheet forming processes is still limited because of their low formability at room temperature and the lack of understanding of the forming process of magnesium alloys at elevated temperatures. In this study, uniaxial tensile tests of the magnesium alloy AZ31B-O at various temperatures were performed to evaluate the mechanical properties of this alloy relevant for forming of magnesium sheets. To construct a FLD (forming limit diagram), a forming limit test were conducted at temperature of 100 and 200 deg. C. For the evaluation of the effects of the punch temperature on the formability of a rectangular cup drawing with AZ31B-O, numerical modelling was conducted. The experiment results indicate that the ...

2007-05-17

401

Hydrogen-plasticity interactions in pearlitic steel: a fractographic and numerical study  

Energy Technology Data Exchange (ETDEWEB)

A fractographic and numerical approach is presented to analyze hydrogen-plasticity interactions in pearlitic steel and to elucidate the main hydrogen transport mechanism in this material under triaxial stress states produced by notches. Fractographic analysis showed that the microdamage produced by the hydrogen was clearly detectable by scanning electron microscopy (SEM), through a specific microscopic topography associated with hydrogen effects (tearing topography surface or TTS). Numerical computations obtained by using an elastic-plastic finite element program gave the progressive spreading of the plastic zone, closely associated with the movement of dislocations. In the majority of cases, the plastic zone (PZ) clearly exceeds the hydrogen affected region (TTS) and has no relation with it. In some tests, however, the hydrogen-induced micro-damage surpasses the only region in which there is dislocation movement, and in this case the net ...

1996-11-30

402

Forced laminar convection in an array of stacked plates  

Energy Technology Data Exchange (ETDEWEB)

A numerical study of laminar flow and heat transfer in an array of stacked rectangular plates is presented. The array is placed in a uniform stream, and the plates are subjected to a constant surface heat flux. This flow configuration is relevant to a number of practical heat transfer devices with finned surfaces. The computations were performed using a finite volume solution of the steady, two-dimensional Navier-Stokes equations and energy equation. A numerical scheme that reduces numerical diffusion is used to discretize the equations. The dominant feature of the flow is the separation, and subsequent reattachment of, the boundary layer, which takes place at Reynolds numbers greater than about 75. The separation first occurs downstream of the leading edge of the plate; then as Re increases, the separation point moves upstream and remains fixed at the leading edge, and the reattachment length increases linearly with Re. ...

1994-04-01

403

Experimental and analytical studies on turbulent heat transfer performance of a fuel rod with spacer ribs for high temperature gas-cooled reactors  

International Nuclear Information System (INIS)

Turbulent heat transfer performance of a fuel rod with three-dimensional trapezoidal spacer ribs for high temperature gas-cooled reactors was studied for various Reynolds numbers using an annular channel at the same coolant condition as the reactor operation, maximum outlet temperature of 1000 C and pressure of 4 MPa, and analytically by a numerical simulation using the k-#epsilon# turbulence model. The turbulent heat transfer coefficients of the fuel rod were 18-80% higher than those of a concentric smooth annulus at a region of Reynolds number exceeding 2000. On the other hand, the predicted average Nusselt number of the fuel rod agreed well with the empirical correlation obtained from the experimental data within a relative error of 10% with Reynolds number of more than 5000. It was verified that the numerical analysis results had sufficient accuracy. Furthermore, the numerical prediction could clarify quantitatively the ...

404

EDP in shaft construction. [Electronic data processing  

Energy Technology Data Exchange (ETDEWEB)

Lining shafts and placing them in a given strata needs extensive computation. Therefore, it is natural that the use of electronic computing and of numerical methods in this mining area started early. For shafts being sunk in non-stable water-bearing strata the deformations and stresses of the freezing wall are analysed. The complex system of an outer lining in the shaft sinking stage is designed with regard to the elastic support of the strata. In cases of strata-embedded systems the tubbing liner can be shaped as the loads require. Here analysis of safety against buckling is very important. If a sliding shaft is built as a composite construction, there are advantages in determining the distribution of the material by numerical methods. The analysis of stability is possible only by numerical methods and could not be solved otherwise. The Finite Element Method proves itself as a very general tool to solve the problem of ...

1987-02-05

405

Determination of Inter-Phase Line Tension in Langmuir Films  

CERN Document Server

A Langmuir film is a molecularly thin film on the surface of a fluid; we study the evolution of a Langmuir film with two co-existing fluid phases driven by an inter-phase line tension and damped by the viscous drag of the underlying subfluid. Experimentally, we study an 8CB Langmuir film via digitally-imaged Brewster Angle Microscopy (BAM) in a four-roll mill setup which applies a transient strain and images the response. When a compact domain is stretched by the imposed strain, it first assumes a bola shape with two tear-drop shaped reservoirs connected by a thin tether which then slowly relaxes to a circular domain which minimizes the interfacial energy of the system. We process the digital images of the experiment to extract the domain shapes. We then use one of these shapes as an initial condition for the numerical solution of a boundary-integral model of the underlying hydrodynamics and compare the subsequent images of the experiment to the ...

2007-01-01

406

Computer modeling of oil spill trajectories with a high accuracy method  

Energy Technology Data Exchange (ETDEWEB)

This paper proposes a high accuracy numerical method to model oil spill trajectories using a particle-tracking algorithm. The Euler method, used to calculate oil trajectories, can give adequate solutions in most open ocean applications. However, this method may not predict accurate particle trajectories in certain highly non-uniform velocity fields near coastal zones or in river problems. Simple numerical experiments show that the Euler method may also introduce artificial numerical dispersion that could lead to overestimation of spill areas. This article proposes a fourth-order Runge-Kutta method with fourth-order velocity interpolation to calculate oil trajectories that minimise these problems. The algorithm is implemented in the OilTrack model to predict oil trajectories following the 'Nissos Amorgos' oil spill accident that occurred in the Gulf of Venezuela in 1997. Despite lack of adequate field ...

1999-07-01

407

Biased power spectrum and bispectrum for an ensemble of three-dimensional scale free numerical simulations  

CERN Document Server

We examine the effect of a threshold bias on the power spectrum and the bispectrum in an ensemble of numerical simulations (Gaussian initial perturbations with power law spectra P(k) \\sim k^n, n=+1, 0, -1, -2) and compare our results with theoretical predictions. Our simulations are evolved sufficiently that on the scale where we apply the threshold the rms fluctuation has developed significantly into the nonlinear regime. Thus, predictions based on perturbation theory do not necessarily apply. Nevertheless, we find our results for the power spectrum, biased power simply amplified by a numerical factor, follow predicted trends, far beyond the regime where perturbation theory is expected to be valid. We find that the biased bispectrum continues to follow the so-called hierarchical form, with reduced three-point amplitude Q \\approx 1 in the strongly nonlinear regime, independent of initial spectrum. In the quasi-linear perturbative regime the ...

1994-01-01

408

A boundary integral approach to unstable solidification  

Energy Technology Data Exchange (ETDEWEB)

We consider the supercooled Stefan problem with a general anisotropic curvature- and velocity-dependent boundary condition on the moving interface. We present numerical methods, based on an integral equation formulation and including a new algorithm for moving curves with curvature-dependent velocity. These methods compute a periodic interface with {ital O}({Delta}{ital t}) accuracy, where {Delta}{ital t} is the time step. Previous work has been limited to short time spans and achieved slightly less than {ital O}({Delta}{ital t}{sup 1/2}) accuracy. Accurate numerical results are seen to agree with the predictions of linear stability theory. This agreement has eluded previous authors, because their numerical methods suffered from grid effects and their linear stability theory was incorrect. We study the long-time evolution of an unstable interface. Our computations exhibit the beginnings of a sidebranching instability when ...

1989-12-01

409

Three-dimensional laminar and turbulent natural convection cooling of heated blocks  

International Nuclear Information System (INIS)

Results of three-dimensional laminar and standard K-#epsilon# turbulent numerical simulations of natural convection cooling of ten cubic aluminum blocks mounted on an insulated plate, facing a shrouding wall, are presented. This geometry is chosen so that comparison with experimental results is possible. The considered problem is of great practical importance because it simulates the case of heated electronic chips, mounted on printed board assemblies, which are frequently encountered in electronic industry applications. The problem is mathematically modeled by the three-dimensional conservation differential equations of mass, momentum, energy and turbulent kinetic energy and dissipation (for the turbulent flow model). IN this paper, these equations are numerically solved by a finite volume method and the laminar and turbulent results are compared to the experimental results obtained with similar parameters.

1990-06-18

410

Three-Dimensional Mixed Convection Heat and Mass Transfer in a Rectangular Duct: Case of Longitudinal Rolls  

British Library Electronic Table of Contents (United Kingdom)

This article presents numerical study of 3-D thermosolutale mixed convection (TSMC) in horizontal rectangular channels. The contribution of this work is to characterize the travelling wave's appearance and to generalize the behavior of Poiseuille-Rayleigh-Benard (PRB) systems for a broad range of dimensionless parameters, which control the double diffusive mixed convection. The numerical results consist of analyzing the flow regimes of the steady longitudinal thermoconvectives rolls for the case of purely thermal mixed convection (TMC) and for both thermal and mass transfer (TSMC). The transition from opposed volume forces to cooperating ones at fixed Rayleigh (Ra), Reynolds (Re), and Lewis (Le) numbers, considerably affects the birth and the development of the longitudinal rolls (noted R/...

2011-01-01

411

Three Dimensional Visualization for the Steam Injection into Water Pool using Electrical Resistance Tomography  

International Nuclear Information System (INIS)

The direct injection of steam into a water pool is a method of heat transfer used in many process industries. The amount of research in this area however is limited to the nuclear industry, with applications relating to reactor cooling systems. Electrical resistance tomography (ERT), a low cost, non-invasive and which has high temporal resolution characteristics, can be used as a visualization tool for the resistivity distribution for the steam injection into water pool such as IRWST. In this paper, three dimensional resistivity distribution of the process is obtained through ERT using iterative Gauss-Newton method. Numerical experiments are performed by assuming different resistive objects in the water pool. Numerical results show that ERT is successful in estimating the resistivity distribution for the injection of steam in the water pool

2010-10-01

412

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

Energy Technology Data Exchange (ETDEWEB)

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

413

The numerical response of breeding Northern Saw-whet Owls Aegolius acadicus suggests nomadism  

British Library Electronic Table of Contents (United Kingdom)

We used a 13-year time series of abundance estimates of breeding Northern Saw-whet Owls (Aegolius acadicus), and of small mammals from central Ontario, Canada, to assess the numerical response of the owls to small-mammal prey species. We found that the finite rate of increase of breeding owls was directly related to estimates of red-backed vole (Myodes gapperi) abundance. Thus, it appeared that the owls were nomadic, and made decisions about where to breed based on vole supply. The owls showed a much weaker response to deer mouse (Peromyscus maniculatus) abundance. Across all years, 55% of variation in owl rate of increase could be uniquely attributed to vole abundance, whereas only 3% could be attributed to mouse abundance. Consistent with the model of nomadism, there was only a weak rela...

2010-01-01

414

The effects of radiation on unsteady mhd convective heat transfer past a semi-infinite vertical porous moving surface with variable suction  

Scientific Electronic Library Online (English)

Abstract in english Numerical solutions for the effects of radiation on a MHD convective heat transfer past a semi-infinite porous plate with a magnetic field are obtained. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The magnetic field acts perpendicular to the porous surface which absorbs the fluid with a suction velocity varying with time. The gov (more) erning equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation technique and then are solved numerically by using the shooting method. The effects of the various parameters on the velocity, temperature profiles as well as the surface skin-friction and surface heat transfer are illustrated graphically.

2008-12-01

415

Standing-Wave Free-Electron Laser Two-Beam Accelerator  

Energy Technology Data Exchange (ETDEWEB)

A free-electron laser (FEL) two-beam accelerator (TBA) is proposed, in which the FEL interaction takes place in a series of drive cavities, rather than in a waveguide. Each drive cavity is 'beat-coupled' to a section of the accelerating structure. This standing-wave TBA is investigated theoretically and numerically, with analyses included of microwave extraction, growth of the FEL signal through saturation, equilibrium longitudinal beam dynamics following saturation, and sensitivity of the microwave amplitude and phase to errors in current and energy. It is found that phase errors due to current jitter are substantially reduced from previous versions of the TBA. Analytic scalings and numerical simulations are used to obtain an illustrative TBA parameter set.

1991-02-01

416

Stabilizing effect of the electron-beam self-fields on the phase-space trajectory in a self-amplified spontaneous emission free-electron laser operating in ultraviolet and x-ray spectral ranges  

International Nuclear Information System (INIS)

A detailed treatment is introduced to measure the dynamic stability of the relativistic electrons in a self-amplified spontaneous emission free-electron laser (FEL) system, which includes the numerical approach of the Kolmogorov entropy (entropy-like quantity), the general equations of motion for a charged particle and the method of monitoring the simulation accuracy. Numerical experiments reveal a new phenomenon that there exists the possibility of the transition from chaotic to non-chaotic phase-space trajectories of the strongly relativistic electrons due to the effect of their self-fields. The adiabatic magnetic field of a one-dimensional wiggler may have a slight influence on the electron transportation in the absence of the FEL fields, but substantially affects the dynamic stability of the electrons in the process of the FEL interaction. Moreover, the laser fields diminish the dynamic stability of the electrons as the FEL interaction ...

2004-02-28

417

Spectrograph for free-electron laser experiments  

International Nuclear Information System (INIS)

The design and construction of a Browne-Buechner type round pole face magnetic electron spectrograph is described. The design is based on the first order transfer properties of the bending magnet including the focal surface, dispersion, magnification and resolution. Second order aberrations are compared wit numerical ray tracing results using measured field data to simulate the magnet. The numerical results are also compared with floating wire measurements on the system. Agreement is within one part in 10"4. Data extraction from the instrument is done with an array of copper detectors placed along the focal surface. The spectrograph has been successfully employed in free-electron laser (FEL) experiments for over a year.

1983-03-21

418

Some mismatches occurred when simulating fractured reservoirs as homogeneous porous media  

Science.gov (United States)

The understanding of transport processes that occur in naturally fractured geothermal systems is far from being complete. Often, evaluation and numerical simulations of fractured geothermal reservoirs, are carried out by assuming equivalent porous media and homogeneous petrophysical properties within big matrix blocks. The purpose of this paper, is to present a comparison between results obtained from numerical studies of a naturally fractured reservoir treated as a simple porous medium and the simulation of some real aspects of the fractured reservoir. A general conclusion outlines the great practical importance of considering even approximately, the true nature of such systems. Our results show that the homogeneous simplified evaluation of the energy resource in a fractured system, could result in unrealistic estimates of the reservoir capacity to generate electricity.

1996-01-24

419

Some mismatches occurred when simulating fractured reservoirs as homogeneous porous media  

Energy Technology Data Exchange (ETDEWEB)

The understanding of transport processes that occur in naturally fractured geothermal systems is far from being complete. Often, evaluation and numerical simulations of fractured geothermal reservoirs, are carried out by assuming equivalent porous media and homogeneous petrophysical properties within big matrix blocks. The purpose of this paper, is to present a comparison between results obtained from numerical studies of a naturally fractured reservoir treated as a simple porous medium and the simulation of some real aspects of the fractured reservoir. A general conclusion outlines the great practical importance of considering even approximately, the true nature of such systems. Our results show that the homogeneous simplified evaluation of the energy resource in a fractured system, could result in unrealistic estimates of the reservoir capacity to generate electricity.

1996-12-31

420

Primary cutaneous Ewing's sarcoma/primitive neuroectodermal tumor manifesting numerous small and huge ulcerated masses: its complete remission by chemotherapy and magnetic resonance imaging findings  

International Nuclear Information System (INIS)

Extraskeletal Ewing's sarcoma (ES) and primitive neuroectodermal tumor (PNET) are widely regarded as clinically and histologically identical tumors which consist of small blue round cells. Extraskeletal ESs/PNETs usually occur in the deep soft tissues of the paraspinal region, chest wall, or lower extremities. However, superficially located cases, so-called cutaneous ESs/PNETs, are exceedingly rare, and the vast majority of the reported cases present as a single small mass. We present magnetic resonance imaging (MRI) findings and clinical course of a unique case of primary cutaneous ES/PNET presenting as numerous huge masses with severe ulceration on them. (orig.)

2010-06-01

421

Phase Information and the Evolution of Cosmological Density Perturbations  

CERN Document Server

The Fourier transform of cosmological density perturbations can be represented in terms of amplitudes and phases for each Fourier mode. We investigate the phase evolution of these modes using a mixture of analytical and numerical techniques. Using a toy model of one-dimensional perturbations evolving under the Zel'dovich approximation as an initial motivation, we develop a statistic that quantifies the information content of the distribution of phases. Using numerical simulations beginning with more realistic Gaussian random-phase initial conditions, we show that the information content of the phases grows from zero in the initial conditions, first slowly and then rapidly when structures become non-linear. This growth of phase information can be expressed in terms of an effective entropy: Gaussian initial conditions are a maximum entropy realisation of the initial power spectrum, gravitational evolution decreases the phase entropy. We show that ...

2000-01-01

422

Particle Swarm Optimization and gravitational wave data analysis: Performance on a binary inspiral testbed  

CERN Document Server

The detection and estimation of gravitational wave (GW) signals belonging to a parameterized family of waveforms requires, in general, the numerical maximization of a data-dependent function of the signal parameters. Due to noise in the data, the function to be maximized is often highly multi-modal with numerous local maxima. Searching for the global maximum then becomes computationally expensive, which in turn can limit the scientific scope of the search. Stochastic optimization is one possible approach to reducing computational costs in such applications. We report results from a first investigation of the Particle Swarm Optimization (PSO) method in this context. The method is applied to a testbed motivated by the problem of detection and estimation of a binary inspiral signal. Our results show that PSO works well in the presence of high multi-modality, making it a viable candidate method for further applications in GW data analysis.

2010-01-01

423

On the role of the Jeffreys'sheltering mechanism in the sustain of extreme water waves  

CERN Document Server

The effect of the wind on the sustain of extreme water waves is investigated experimentally and numerically. A series of experiments conducted in the Large Air-Sea Interactions Facility (LASIF) showed that a wind blowing over a strongly nonlinear short wave group due to the linear focusing of a modulated wave train may increase the life time of the extreme wave event. The expriments suggested that the air flow separation that occurs on the leeward side of the steep crests may sustain longer the maximum of modulation of the focusing-defocusing cycle. Based on a Boundary-Integral Equation Method and a pressure distribution over the steep crests given by the Jeffreys'sheltering theory, similar numerical simulations have confirmed the experimental results

2006-01-01

424

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

International Nuclear Information System (INIS)

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 are expected to appear. Moreover, it is found that the frequency ...

425

Numerical simulation of the flow field in a high specific speed radial fan; Numerische Simulation der Stroemung in einem Radialventilator mit hoher spezifischer Drehzahl  

Energy Technology Data Exchange (ETDEWEB)

The present paper describes the application of the commercial CFD-code FLUENT 6.1 to the numerical simulation of the flow field in a high specific speed radial fan. Two-dimensional as well as three-dimensional computations are performed using the steady 'Frozen-Rotor method' as well as the unsteady 'Sliding-Mesh method'. The predicted performance curves of the radial fan are compared with the results obtained from measurements on a test stand. Due to the relatively low computation times, the 'Frozen-Rotor method' can be used routinely for design purposes. The results of this approach can be improved if the leakage flow through the gap between the inlet nozzle and the impeller is taken into account. (orig.)

2005-11-01

426

Numerical simulation of slagging films in the Aachen pressurized coal combustion facility  

Energy Technology Data Exchange (ETDEWEB)

Combined gas and steam turbine processes based on direct coal firing show a high thermal efficiency. At RWTH Aachen, University of Technology, an experimental test furnace has been built to investigate the pressurized pulverized coal combustion (PPCC). The PPCC-facility has been constructed as a slag tap furnace. Particles hitting the walls at temperatures above the melting point cause slagging depositions and create a film flowing down the reactor walls. As a part of the PPCC-program different mathematical models have been developed and implemented into the CFD-code FLUENT to predict the behavior of slag films at the furnace walls. Numerical strategies and the mathematical models used are described in detail. 12 refs., 9 figs.

2001-07-01

427

Numerical simulation of conformational variability in biopolymer translocation through wide nanopores  

CERN Document Server

Numerical results on the translocation of long biopolymers through mid-sized and wide pores are presented. The simulations are based on a novel methodology which couples molecular motion to a mesoscopic fluid solvent. Thousands of events of long polymers (up to 8000 monomers) are monitored as they pass through nanopores. Comparison between the different pore sizes shows that wide pores can host a larger number of multiple biopolymer segments, as compared to smaller pores. The simulations provide clear evidence of folding quantization in the translocation process as the biopolymers undertake multi-folded configurations, characterized by a well-defined integer number of folds. Accordingly, the translocation time is no longer represented by a single-exponent power law dependence on the length, as it is the case for single-file translocation through narrow pores. The folding quantization increases with the biopolymer length, while the rate of translocated beads at each ...

2009-01-01

428

Numerical simulation of a pulsed corona discharge plasma  

Science.gov (United States)

In this paper we study theoretically a pulsed corona discharge plasma in air at atmospheric pressure. A self consistent one-dimensional model, using a flux-corrected transport numerical scheme, is presented to achieve it. The charged particle kinetics in this model are described by one-dimensional continuity equations coupled with Poisson's equations. The spatio-temporal local field, charge density variations and the velocity profile of an ionizing front are calculated to describe the dynamical behavior of corona discharge plasmas. The simulation results of a wire-in-cylinder corona discharge plasma explain the physical mechanisms of discharge processes. These results may also be apply to obtain the optimizing parameters for designing the plasma reactor.

2001-10-01

429

Numerical modeling of scanning laser-induced melting, vaporization and resolidification in metals subjected to step heat flux input  

Energy Technology Data Exchange (ETDEWEB)

We present a 1-D heat transfer, melting, vaporization and resolidification model describing the interaction of a scanning continuous-wave laser with a metal surface wherein the beam power is constant. A physical model based on the Stefan problem is developed with appropriate boundary conditions. The effects of processing parameters on process variables are investigated numerically by varying beam diameters, scan speeds and substrate temperatures for Nickel. Relations are derived for the times to initiate melting, to initiate vaporization, to reach maximum melting depth, for melting-resolidification, and for maximum melting and vaporization depths. Surface temperatures are compared with approximate closed form solutions. (Author)

2004-09-01

430

Numerical modeling of a MEMS actuator considering several magnetic force calculation methods  

British Library Electronic Table of Contents (United Kingdom)

Purpose - The purpose of this paper is to investigate the accuracy of different force calculation methods and their impact on mechanical deformations. For this purpose, a micrometer scaled actuator is considered, which consists of a micro-coil and of a permanent magnet (PM) embedded in a deformable elastomeric layer. Design/methodology/approach - For the magnetic field evaluation a hybrid numerical approach (finite element method/boundary element method (FEM/BEM) coupling and a FEM/BEM/Biot-Savart approach) is used, whereas FEM is implemented for the mechanical deformation analysis. Furthermore, for the magneto-mechanical coupling several force calculation methods, namely the Maxwell stress tensor, the virtual work approach and the equivalent magnetic sources methods, are considered and co...

2011-01-01

431

Numerical methods for thermal-hydraulics and structure in nuclear engineering  

International Nuclear Information System (INIS)

Designs of nuclear reactor plants aim for high performance under safety consideration. Because of large scale and high pressure/temperature conditions, data from costly mockup tests have been required to verify simulation codes of systems and components. Establishment of design by analysis (DBA) in nuclear engineering is required for development of next generation nuclear reactors. Recent powerful computers and simulation technique enable numerical analyses to predict realistic behaviors of thermo-fluid flow, structure and do on. The present report describes resent simulation results of complex gas-liquid two-phase flow, large scale structure dynamics and fluid-structure interaction. (author)

2008-06-01

432

Numerical heat transfer studies of the fatty acids for different heat exchanger materials on the performance of a latent heat storage system  

Energy Technology Data Exchange (ETDEWEB)

Theoretical investigations of fatty acids as a phase change material (PCM) for energy storage system have been conducted in this study. The selected fatty acids were capric acid, lauric acid, myristic acid, palmitic acid and stearic acid. For the two-dimensional simulation model based on the enthalpy approach, calculations have been made for the melt fraction with conduction only. Glass, stainless steel, tin, aluminium mixed, aluminium and copper were used as heat exchanger materials in the numerical calculations. Theoretical results show that capric acid was found good compatibility with latent heat storage system. The large value of thermal conductivity of heat exchanger materials did not make significant contribution on the melt fraction. (author)

2005-11-01

433

Numerical evaluation of effective unsaturated hydraulic properties for fractured rocks  

Energy Technology Data Exchange (ETDEWEB)

To represent a heterogeneous unsaturated fractured rock by its homogeneous equivalent, Monte Carlo simulations are used to obtain upscaled (effective) flow properties. In this study, we present a numerical procedure for upscaling the van Genuchten parameters of unsaturated fractured rocks by conducting Monte Carlo simulations of the unsaturated flow in a domain under gravity-dominated regime. The simulation domain can be chosen as the scale of block size in the field-scale modeling. The effective conductivity is computed from the steady-state flux at the lower boundary and plotted as a function of the averaging pressure head or saturation over the domain. The scatter plot is then fitted using van Genuchten model and three parameters, i.e., the saturated conductivity K{sub s}, the air-entry parameter {alpha}, the pore-size distribution parameter n, corresponding to this model are considered as the effective K{sub s}, effective {alpha}, and effective n, respectively.

2009-01-01

434

Numerical and experimental investigation of shellside characteristics for RODbaffle heat exchanger  

Energy Technology Data Exchange (ETDEWEB)

RODbaffle heat exchanger is a kind of shell-and-tube heat exchanger with eminent performance. Because of the characteristics of tube bundle support structure, fluid flow on shellside is longitudinal and periodical, and fluid flow is of symmetry in landscape orientation. According to the fluid flow characteristics on shellside and ignoring the impact of inlet, outlet and shell wall, a periodic flow unit duct was taken as the simplified model of the shellside to perform numerical simulation by using CFD code, FLUENT. It was found that the both errors in magnitude of the main fluid velocities and heat transfer coefficients between results of simulation and that of experiment or correlations are less than 10%, and the errors of pressure drop between simulation and correlation are no more than 20%. The detailed characteristics and relation of fluid flow and heat transfer on shellside of the RODbaffle heat exchanger were analyzed using the simulation results. (author)

2008-05-15

435

Modelling of MeV alpha particle energy transfer to lower hybrid waves  

Energy Technology Data Exchange (ETDEWEB)

The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. Here we calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favourable for wave amplification from alpha energy. We find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy transfer, is investigated. This technique is shown to offer a large potential benefit. (Author).

1994-05-01

436

Modelling of MeV alpha particle energy transfer to lower hybrid waves  

International Nuclear Information System (INIS)

The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. Here we calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favourable for wave amplification from alpha energy. We find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy transfer, is investigated. This technique is shown to offer a large potential benefit. (Author).

437

Modelling and migration of seismic data in transversely isotropic media; Modelamento e migracao de dados sismicos em meios transversalmente isotropicos  

Energy Technology Data Exchange (ETDEWEB)

The forward modelling and the prestack reverse time migration of seismic P-SV wave field was carried out in 2-D models of isotropic and anisotropic media which allow separation of P-SV and SH motion. The P-SV wave field can be described by a system of hyperbolic, first order differential equations in terms of particle velocity and stress. The system of five equations and five unknowns, namely horizontal (U) and vertical (V) velocity components, and three components of stress (T{sub xx}, T-z{sub z} and T{sub xz}) was solved numerically using second order space and forth order time finite differences operators. In order to attenuate numerical dispersion, a staggered grid was used. (author). 48 refs., 5 figs

1993-12-31

438

Modeling, numerical simulation and experimental verification of the unsteady cooling of a solid body in quiescent ambient air  

Energy Technology Data Exchange (ETDEWEB)

The scope of the present article is two-fold. Firstly, to conduct an experiment to provide the temperature-time history of the cooling of a hot ball bearing in quiescent ambient air. Secondly, to predict the temporal variation of the bearing under the hypothesis of natural convection, radiation or natural convection coexists with radiation for a non-vanishing total hemispherical emissivity of the surface of the bearing. Numerical solutions of the three governing nonlinear lumped heat equations were carried out with a Runge-Kutta-Fehlberg (RKF45) algorithm accounting for automatic step size control. The experimental data was obtained with chrome steel ball bearings of diameter 0.953 cm (7/16 in) heated in an electric oven to a pre-set temperature. The heated bearing was exposed later to ambient air at atmospheric temperature and pressure. (orig.)

2004-07-01

439

Modeling of MeV alpha particle energy transfer to lower hybrid waves  

Energy Technology Data Exchange (ETDEWEB)

The interaction between a lower hybrid wave and a fusion alpha particle displaces the alpha particle simultaneously in space and energy. This results in coupled diffusion. Diffusion of alphas down the density gradient could lead to their transferring energy to the wave. This could, in turn, put energy into current drive. An initial analytic study was done by Fisch and Rax. Here the authors calculate numerical solutions for the alpha energy transfer and study a range of conditions that are favorable for wave amplification from alpha energy. They find that it is possible for fusion alpha particles to transfer a large fraction of their energy to the lower hybrid wave. The numerical calculation shows that the net energy transfer is not sensitive to the value of the diffusion coefficient over a wide range of practical values. An extension of this idea, the use of a lossy boundary to enhance the energy transfer, is investigated. This technique is ...

1993-10-01

440

Mixed convection in a horizontal rectangular channel - Experimental and numerical velocity distributions  

Science.gov (United States)

Mixed convection in a rectangular channel (width/height = 2) with bottom-heated and top-cooled sections is studied by laser Doppler anemometry in nitrogen at Ra = 22,200 and Re = 18.75, 36, and 54. At the lower Re values, symmetry breaking is observed in steady but spatially oscillating flows that prevail over a certain distance from the leading edge of the differentially heated section. Further downstream, unsteady flows are found even for Re = 18.75. Numerical models are used to investigate the effects of adiabatic, conducting (with a conductive-convective heat transfer coefficient), and perfectly conducting side walls; channel tilts and Prandtl number dependence. Good agreement between calculations and experiment is obtained for longitudinal convective roll velocities. The transverse velocities are found to be independent of Re.

1992-06-01

441

Measurement of the dark matter velocity anisotropy profile in galaxy clusters  

CERN Document Server

Dark matter particles form halos that contribute the major part of the mass of galaxy clusters. The formation of these cosmological structures have been investigated both observationally and in numerical simulations, which have confirmed the existence of a universal mass profile. However, the dynamic behaviour of dark matter in halos is not as well understood. We have used observations of 16 equilibrated galaxy clusters to show that the random velocities of dark matter particles are larger on average along the radial direction than along the tangential, and that the magnitude of this velocity anisotropy is radially varying. Our measurement implies that the collective behaviour of dark matter particles is fundamentally different from that of normal particles and the radial variation of the anisotropy velocity agrees with the predictions of numerical simulation.

2008-01-01

442

Mathematical modeling of the behavior of geothermal systems under exploitation  

Energy Technology Data Exchange (ETDEWEB)

Analytical and numerical methods have been used in this investigation to model the behavior of geothermal systems under exploitation. The work is divided into three parts: (1) development of a numerical code, (2) theoretical studies of geothermal systems, and (3) field applications. A new single-phase three-dimensional simulator, capable of solving heat and mass flow problems in a saturated, heterogeneous porous or fractured medium has been developed. The simulator uses the integrated finite difference method for formulating the governing equations and an efficient sparse solver for the solution of the linearized equations. In the theoretical studies, various reservoir engineering problems have been examined. These include (a) well-test analysis, (b) exploitation strategies, (c) injection into fractured rocks, and (d) fault-charged geothermal reservoirs.

1982-01-01

443

Investigation of the magnetic field response from eddy current inspection of defects  

British Library Electronic Table of Contents (United Kingdom)

Eddy current testing is one of the most widely used methods in non-destructive testing for the inspection of conductive materials. Numerical modelling of eddy current testing has emerged as an important approach alongside experimental studies. This paper investigates an application of numerical modelling and experimental study as a means of the quantitative non-destructive evaluation (QNDE) of defects in conductive samples. There are two methods of measuring eddy current response, more commonly by measuring the change in impedance of the eddy current probe coil, or as used in this work, by measuring the change in magnetic field directly using magnetic field sensors such as superconducting quantum interference devices, giant magneto resistance, or as in this case Hall sensors. Specifically,...

2011-01-01

444

Influence of chemical reaction and thermal radiation on the heat and mass transfer in MHD micropolar flow over a vertical moving porous plate in a porous medium with heat generation  

British Library Electronic Table of Contents (United Kingdom)

An analysis is presented for the effects of chemical reaction and thermal radiation on hydromagnetic free convection heat and mass transfer for a micropolar fluid via a porous medium bounded by a semi-infinite vertical porous plate in the presence of heat generation. The plate moves with a constant velocity in the longitudinal direction and the free stream velocity follows an exponentially small perturbation law. A uniform magnetic field acts perpendicularly to the porous surface in which absorbs the micropolar fluid with a suction velocity varying with time. Analytical expressions are computed numerically. Numerical calculations are carried out the purpose of the discussion of the results which are shown on graphs and the effects of the various dimensionless parameters entering into the p...

2009-01-01

445

Heat generation and temperature prediction in metal cutting: A review and implications for high speed machining  

British Library Electronic Table of Contents (United Kingdom)

Determination of the maximum temperature and temperature distribution along the rake face of the cutting tool is of particular importance because of its controlling influence on tool life, as well as, the quality of the machined part. Numerous attempts have been made to approach the problem with different methods including experimental, analytical and numerical analysis. Although considerable research effort has been made on the thermal problem in metal cutting, there is hardly a consensus on the basics principles. The unique tribological contact phenomenon, which occur in metal cutting is highly localized and non-linear, and occurs at high temperatures, high pressures and high strains. This has made it extremely difficult to predict in a precise manner or even assess the performance of va...

2006-01-01

446

Five Special Types of Orbits Around Mars  

CERN Document Server

The abstract is additional with repect to the paper published in JGCD. Ordinary Earth satellites are usually placed into five categories of special orbits: sun-synchronous orbits, orbits at the critical inclination, frozen orbits, repeating ground track orbits, and geostationary orbits. This paper investigates their counterparts around Mars and examines the basic nature of these orbits, which are of special interest for missions conducted around Mars, including Mars reconnaissance. Mars' gravity field is much more complicated, with relatively smaller J2, compared to Earth's, which makes the behaviors of these Martian orbits different from those of Earth. Analytical formulations and numerical simulations are used to analyze these Martian orbits and compare them with their Earth counterparts. First, mean element theory is employed to describe variations of orbital elements and give the constraint conditions for achieving these special orbits. Then, ...

2011-01-01

447

Experimental studies and numerical modeling of the specimen and grain size effects on the flow stress of sheet metal in microforming  

British Library Electronic Table of Contents (United Kingdom)

In this research, the interactive effect of grain and specimen sizes on the flow stress of sheet metal in microforming is investigated via the tensile test of pure copper and numerical modeling. Models based on different assumptions are proposed to analyze the size effect phenomenon. It is found that the flow stress decreases linearly with the decrease of the ratio of specimen to grain sizes. The grain boundary thickness decreases and its volume fraction increases with the decrease of grain size. The variation of grain boundary thickness is not proportional to the variation of grain size. Furthermore, the fraction of grain boundary increases with the strain and the ratio of specimen to grain sizes. Based on the FE simulation, it is found that the simulated flow stress, which is modeled bas...

2011-01-01

448

Experimental and Numerical Study of Shot Peened Thin Hard-Coated Components  

British Library Electronic Table of Contents (United Kingdom)

A test bench was designed and assembled to carry out impact tests on samples and components. The system allows simple and rapid adjustment of the test parameters, such as the shot size and air pressure, with good repeatability of the results. Tests on steel and light alloys were carried out under both as-produced condition and on thin hard-coated samples. Significant reductions in dimple dimensions were seen after coating. FE models simulating the experiments overestimated the dimple depths, although the parameter trend was satisfactorily captured. The residual stresses from coating and shot peening determined numerically are believed to have been proven effective against fatigue.

2011-01-01

449

Evaluation method for corrosion resistance of zirconium alloy  

International Nuclear Information System (INIS)

The present invention concerns a method of evaluating corrosion resistance of a zirconium alloy easily and in a short period of time. An anode polarization curve of the zirconium alloy is measured to obtain an anode polarization curve expressed by logarithm. The curve is converted to a potential-current density curve expressed by absolute values. The peak area in the curve of the converted potential-current density is indicated by numerical values. Further, the corrosion resistance of the zirconium alloy is evaluated based on the peak area converted into the numerical values as a reference. This method is based on the finding that the peak area has a close relation with nodular corrosion resistance, and the corrosion resistance can be judged with respect to a specific zircaloy-2. (T.M.).

1993-03-26

450

Effect of initial conditions, boundary conditions and thickness on the moisture buffering capacity of spruce plywood  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the moisture buffering capacity of spruce plywood is measured by recording the change in mass of a test specimen when the air relative humidity (RH) is changed between 33% RH and 75% RH. The aim is to represent diurnal cycles in indoor humidity with 33% RH maintained for 16 h and 75% RH maintained for 8 h. Measurements are taken using two different apparatuses, which provide different convective transfer coefficients between the air and the plywood, and the results are compared to a numerical model for validation. The validated numerical model is then used to investigate the effect of initial conditions, boundary conditions and thickness on the moisture buffering capacity of plywood. The results show that the buffering capacity of plywood depends on the initial conditions and thickness of the plywood as well as the surface film coefficient and humidity cycle. (author)

2006-07-01

451

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

Energy Technology Data Exchange (ETDEWEB)

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

452

Development work currently being carried out on the time-dependent finite-element diffusion code TRANSFUSION for nuclear oil well logging problems  

Energy Technology Data Exchange (ETDEWEB)

The code is being developed starting from the steady-state finite element code FENDER for the solution of the diffusion equation by extending it to become time-dependent. The numerical solution of the time-dependent multigroup diffusion equations within TRANSFUSION is performed at the present stage of development by using a backward difference scheme for the time variable, leading to a rearrangement of FENDER by adding a new loop over time steps. The code retains the multigroup coupled neutron-gamma features of FENDER, and provides a consistent two-, and quasi three-dimensional numerical solution of both static and time-dependent multigroup diffusion equations. (orig./DG)

1993-04-01

453

Determination of critical length for pipe whip design  

Energy Technology Data Exchange (ETDEWEB)

Design of pipe whip restraints requires a knowledge of the maximum allowable unsupported pipe length. This paper presents a numerical method for calculating this critical length of the pipe. Salient features of the method are: (1) as a flow rounds an elbow, it exerts a transverse kick and an axial thrust to the pipe, both the axial thrust and the bending moment are considered; (2) the jet force is applied in an abrupt manner, the dynamic amplification factor (DAF) is determined from the load-deflection (H-{Delta}) curve of the pipe, by taking into consideration large strain, large deformation and the nonlinear stress-strain relationship of the piping material; (3) the ultimate capacity of the pipe under the combined action of an axial force and a bending moment is governed by an interaction formula. The maximum unsupported pipe length is calculated from this formula. Only the formulas and derivation are presented. Numerical results and design ...

1995-11-01

454

Deep-level defects and numerical simulation of radiation damage in GaAs solar cells  

Energy Technology Data Exchange (ETDEWEB)

A review of the deep-level defects observed in both electron- and proton-irradiated GaAs solar cells is presented. Studies of the effects of periodic and continuous thermal annealing on the radiation-induced electron and hole traps and the recombination parameters in GaAs solar cells were made for a wide range of electron and proton energies, fluence, annealing temperature and annealing time. A refined model for numerical simulations of the displacement damage was developed for computing the defect density and the cell parameters in the electron- and proton-irradiated GaAs solar cells. Excellent agreement was obtained between the calculated values and the experimental data for the proton-irradiated GaAs solar cells. (orig.).

1991-09-01

455

Continuous method development and numerical study of HHV water gas production by pulverized coal  

British Library Electronic Table of Contents (United Kingdom)

In energy industries, it is always of difficulty to produce high heat value(HHV) gas continuously using pulverized coal. In this paper, a new type furnace for partitioned alternative gasification using pulverized coal is developed, in which the oxidation and reduction reaction occur alternatively with the dropping of pulverized coal and finally HHV gas could be continuously obtained at the reduction zone exit and low heat value(LHV) gas at the oxidation zone exit. Furthermore, the gasification characteristics and their factors in furnace are numerically simulated under two dimensional model with a self-coded program, based on heat, mass and energy transfer as well as reaction principles. It is found that the producing rate of HHV gas is 1.10Nm3/kg with heat value of 11.72MJ/Nm3, however, t...

2011-01-01

456

Comparative study of three dimensional numerical simulations of particle dispersion in a turbulent air flow  

International Nuclear Information System (INIS)

This paper describes the study of particles' dispersion in an isotropic turbulent flow. The particle's motion and the turbulent flow characteristics are calculated independently. While the particles' displacement is computed by the author's code, the flow is simulated with a commercial code : PowerFLOW. The particles and the flow are coupled through the relative velocity component of the aerodynamic force. When the simulated flow is turbulent, a turbulence regeneration model is used in order to get the flow instantaneous velocity. Validation of the method is done by comparing the particles' dispersion obtained with experimental results from literature and with the results calculated by FLUENT. Good accordance is found between numerical studies and experimental results. However, comparison between results of PowerFLOW coupled to the author's code and results from FLUENT shows differences when the particle's path goes through the turbulent boundary layer. (author)

2004-05-09

457

Code Verification by the Method of Manufactured Solutions  

Energy Technology Data Exchange (ETDEWEB)

A procedure for code Verification by the Method of Manufactured Solutions (MMS) is presented. Although the procedure requires a certain amount of creativity and skill, we show that MMS can be applied to a variety of engineering codes which numerically solve partial differential equations. This is illustrated by detailed examples from computational fluid dynamics. The strength of the MMS procedure is that it can identify any coding mistake that affects the order-of-accuracy of the numerical method. A set of examples which use a blind-test protocol demonstrates the kinds of coding mistakes that can (and cannot) be exposed via the MMS code Verification procedure. The principle advantage of the MMS procedure over traditional methods of code Verification is that code capabilities are tested in full generality. The procedure thus results in a high degree of confidence that all coding mistakes which prevent the equations from being solved correctly ...

2000-06-01

458

Calculation of electromagnetic force in electromagnetic forming process of metal sheet  

International Nuclear Information System (INIS)

Electromagnetic forming (EMF) is a forming process that relies on the inductive electromagnetic force to deform metallic workpiece at high speed. Calculation of the electromagnetic force is essential to understand the EMF process. However, accurate calculation requires complex numerical solution, in which the coupling between the electromagnetic process and the deformation of workpiece needs be considered. In this paper, an appropriate formula has been developed to calculate the electromagnetic force in metal work-piece in the sheet EMF process. The effects of the geometric size of coil, the material properties, and the parameters of discharge circuit on electromagnetic force are taken into consideration. Through the formula, the electromagnetic force at different time and in different positions of the workpiece can be predicted. The calculated electromagnetic force and magnetic field are in good agreement with the numerical and experimental ...

2010-06-15

459

Breathers in Josephson junction ladders: Resonances and electromagnetic wave spectroscopy  

DEFF Research Database (Denmark)

We present a theoretical study of the resonant interaction between dynamical localized states (discrete breathers) and linear electromagnetic excitations (EE's) in Josephson junction ladders. By making use of direct numerical simulations we find that such an interaction manifests itself by resonant steps and various sharp switchings (voltage jumps) in the current-voltage characteristics. Moreover, the power of ac oscillations away from the breather center (the breather tail) displays singularities as the externally applied dc bias decreases. All these features may be mapped to the spectrum of EE's that has been derived analytically and numerically. Using an improved analysis of the breather tail, a spectroscopy of the EE's is developed, The nature of breather instability driven by localized EE's is established.

2001-01-01

460

Basic study on heat transfer characteristics of liquid Na in a decay-heat removal system of LMFBR  

Energy Technology Data Exchange (ETDEWEB)

A numerical analysis is performed to clarify the heat transfer characteristics of combined convection around the tubes which form a single row perpendicularly arranged to a forced flow in the direction of gravity. A boundary-fitted coordinate transformation technique is adopted to solve the governing equations numerically. It is found in the case of liquid sodium that gravity-induced flow gives no substantial effect to heat transfer augmentation in a low Reynolds number region while it can be sufficiently expected in the ordinary fluids in the same Reynolds number region. This means that such heat transfer augmentation as expected in ordinary fluids can not be realized when crossflow-type heat exchangers installed for decay-heat removal operates in a low Reynolds number region.

1988-02-01

461

Application of Combined Enhanced Techniques for Design of Highly Efficient Air Heat Transfer Surface  

British Library Electronic Table of Contents (United Kingdom)

In order to reduce the size and cost of heat exchangers, an air-side wavy fin-and-tube heat transfer surface with three-row tubes needs to be replaced by two-row tubes with some appropriate enhancing techniques. The major purpose of the present paper is to search for such new structure by numerical simulation. First, longitudinal vortex generators of Delta-winglet type are tried. The influence of number and of arrangement of the winglets on the performance of the heat transfer surface is studied in detail. The numerical results show that the fin with two winglets aligned spanwise in the front and rear of each tube (Fin W6) has higher heat transfer capability than other enhanced structures with vortex generators, but it still unable to meet the heat transfer requirement. Then a combination ...

2012-01-01

462

An assessment of health impacts of electrical power transmission lines  

International Nuclear Information System (INIS)

The types of investigations undertaken to test for possible biological effects of extremely low frequency electric fields have been numerous. However, neither animal and plant experimentation nor clinical studies nor experience with operating extremely high voltage transmission lines have to date provided convincing evidence of a harmful effect from exposure to electric fields associated with transmission lines in spite of numerous attempts to find such effects. Analysis of internal fields and currents supports these observations as the levels appear to be too low to affect mammalian cells. Thus, while one can never prove the negative (i.e. that there is no effect), the overwhelming body of evidence indicates that the electric fields associated with high-voltage lines have no deleterious biological effects. (author).

1981-06-26

463

Absorption of CO/sub 2/ in aqueous solutions of mixtures of alkanolamines  

Energy Technology Data Exchange (ETDEWEB)

The bulk removal of CO/sub 2/ from industrial gases is a frequently applied process in the field of gas-treating. Usually chemical solvents are used in order to increase both the solvent-loading capacity and the absorption rate. These solvents often are aqueous solutions of alkanolamines. The loaded-liquid is regenerated at high temperatures with the aid steam. In the present study absorption rates are experimentally determined in various mixtures of amines over a wide range of concentrations. Simultaneously, a model was developed for the description of mass transfer accompanied by parallel reversible chemical reactions. The equations of this mass transfer model could not be solved analytically and therefore numerical techniques were used to obtain an exact description of this process. This model also includes the asymptotic situations of homogeneous catalysts and shuttle mechanism for which in the literature several approximate solutions have been presented. The ...

1988-01-01

464

A universal nutrient application strategy for the bioremediation of oil-polluted beaches  

British Library Electronic Table of Contents (United Kingdom)

Biostimulation by nutrient application is a viable technology for restoring oil-contaminated beaches. Maximizing the nutrient residence time is key for achieving a rapid cost-effective cleanup. We considered the nutrient injection strategy through a perforated pipe at the high tide line and we simulated numerically beach hydraulics, which allowed us to estimate the optimal injection flow rate of nutrient solution. Our results indicate that the optimal application is one that starts following the falling high tide and lasts for half tidal cycle. The saturated wet-front of the nutrient solution on the beach surface would move seaward with the same speed of the falling tide keeping a constant distance with the tide line. The numerical results were generalized to beaches of wide ranges of hydr...

2007-01-01

465

A prediction of the acoustical properties of induction cookers based on an FVM-LES-acoustic analogy method  

British Library Electronic Table of Contents (United Kingdom)

The FVM-LES-acoustic analogy method (FVM-LES-AAM), which is a hybrid prediction technique for the acoustical property computation, is presented and performed in this paper. The FVM-LES-AAM was developed by combining the finite volume method (FVM), the large eddy simulation (LES), and the Ffowcs Williams-Hawkings analogy algorithm (FWH-AA). To predict the acoustical properties of induction cookers, the FVM is used for discretizing the calculation field and building numerical equations, and the LES and FWH-AA are performed for computing the sound sources and predicting the far-field sound, respectively. Using the FVM with the unstructured grids method to discretize the control equation of Navier-Stokes was introduced for illuminating the above numerical simulation procedure. To prove the FVM...

2011-01-01

466

A numerical solution of unsteady MHD convection heat and mass transfer past a semi-infinite vertical porous moving plate using element free Galerkin method  

British Library Electronic Table of Contents (United Kingdom)

In this paper, the unsteady MHD free convection heat and mass transfer of viscous fluid flowing through a Darcian porous regime adjacent to a moving vertical semi-infinite plate under Soret and Dufour effect have been examined. Viscous dissipation effects are included in the energy equation. A uniform magnetic field is applied transversely to the direction of the flow. The differential equations governing the problem have been transformed by a similarity transformation into a system of non-dimensional differential equations which are solved numerically by element free Galerkin method. The influence of Grashof number (Gr), magnetic parameter (M), heat absorption parameter (Q), permeability parameter (K), Schmidt number (Sc), Soret number (Sr), and Dufour number (Du) on the velocity, tempera...

2010-01-01

467

A basic study on heat transfer characteristics of liquid Na in a decay-heat removal system of LMFBR  

International Nuclear Information System (INIS)

A numerical analysis is performed to clarify the heat transfer characteristics of combined convection around the tubes which form a single row perpendicularly arranged to a forced flow in the direction of gravity. A boundary-fitted coordinate transformation technique is adopted to solve the governing equations numerically. It is found in the case of liquid sodium that gravity-induced flow gives no substantial effect to heat transfer augmentation in a low Reynolds number region while it can be sufficiently expected in the ordinary fluids in the same Reynolds number region. This means that such heat transfer augmentation as expected in ordinary fluids can not be realized when crossflow-type heat exchangers installed for decay-heat removal operates in a low Reynolds number region. (author).

1988-01-01

468

A Study on the Power System Stabilizer Design using Object-Oriented Method  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we have designed power system stabilizer (PSS) using object-oriented method. There are several types of power system stabilizer, A proportional-integral (PI) controller is very simple for practical implementation. Therefore it has been widely employed by the industry. The methods of obtaining the gains (Ki,Kp) of PI controller are root-locus method and sub-optimal regulator approach. But these methods are cannot be applicable to nonlinear system and faulted power system. So we proposed a new method which can be applied to nonlinear system by numerical analysis method. The method of dynamic system simulation by numerical method is very difficult and complex. We proposed flexible simulation method for complex power system analysis using object-oriented programming (OOP) and applied to PI controller design. (author). 7 refs., 14 figs., 2 tabs.

1999-06-01

469

A Study on A Semi-Submersible Floating Offshore Wind Energy Conversion System  

Energy Technology Data Exchange (ETDEWEB)

A new semi-submersible floating structure is proposed on which three wind turbine towers are installed. This paper presents a basic characteristic of the wave-induced motion of this semi-submersible floating structure via. numerical computations and 1/150 scaled rigid model experiments in a wave tank. In the numerical computations, nonlinear damping effect due to drag forces modeled by the Morison's formula is considered in the equation of motion, where the linear hydrodynamic forces are obtained from the Green's function model. As a result, the response characteristics around the resonant frequency region were successfully improved. In addition to such basic examination, major results of feasibility studies, including the structural stability for severe wave conditions and the long-term fatigue limit state, are presented for a realistic situation.

2007-07-01

470

Towards a dissipativity framework for power system stabilizer design  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a dissipativity-based framework for the study of low-frequency oscillations in power systems and for power system stabilizer design. This framework leads to a robust controller design formulation, amenable to both H{sub {infinity}} and QFT tools. An illustrating numerical example presents QFT based design for a widely used benchmark two area, four machine power system.

1996-11-01

471

The formation of counterrotating cores in elliptical galaxies  

International Nuclear Information System (INIS)

The mechanism proposed by Kormendy (1984) for the formation of counterrotating cores in elliptical galaxies is investigated using self-consistent numerical simulations of mergers between a high- and a low-luminosity elliptical galaxies. The conditions for a counterrotation to appear are determined, observational properties of the remnants are described, and the evolution of the structural and kinematic parameters of the larger galaxy is analyzed. It is shown that a counterrotation results only when the merging orbits are retrograde, due to a large change in the secondary spin during the merger. 36 refs.

472

The effects of spatial location of defect states on the switching characteristics of amorphous and polycrystalline silicon thin film transistors: A numerical simulation using AMPS 2-D  

Energy Technology Data Exchange (ETDEWEB)

We demonstrate a two-dimensional device simulator for MOSFET structures that incorporates models for defect distributions and show predicted effects on device switching performance for various spatial distributions of defects in amorphous and polycrystalline silicon.

1994-06-01

473

The different structural scales of the breast and their impact on time-of-flight and diffraction tomography  

Energy Technology Data Exchange (ETDEWEB)

Ultrasound tomography is an attractive imaging method for the detection of breast cancer. The complex anatomy of the breast with its different spatial scales and material property contrasts make accurate reconstructions very challenging. This paper proposes a hybrid approach whereby Travel-of-Flight and Diffraction Tomography are combined together to achieve high-resolution and high-accuracy sound-speed reconstructions. The method is validated with several numerical phantoms.

2010-01-01

474

Studies on a new kind of fuzzy power system stabilizer  

Energy Technology Data Exchange (ETDEWEB)

This paper is concerned with the application of a new fuzzy inference method to the design of fuzzy power system stabilizer. Based on Truth-Value-Flow-Inference (TVFI), a fuzzy logic controlled power system stabilizer is proposed to enhance the stability of power system with weak or negative damping. The design of the proposed fuzzy power system stabilizer is presented. Numerical simulation results are presented and compared with two other kinds of fuzzy power system stabilizers. (author)

1998-12-31

475

Solution of Bohr's collective Hamiltonian for transitional odd-mass nuclei  

International Nuclear Information System (INIS)

A numerically feasible method, based on the use of deformed phonons, is developed for the diagonalization of the collective quadrupole Hamiltonian for a system with an odd particle coupled to an anharmonic even core. Examples: the transition from prolate to oblate via #gamma#-unstable shapes and furthermore the hsub(9/2) spectra of the nuclei "1"8"7Ir and "1"9"7Tl. (Auth.).

476

Simulation of arsenic diffusion during rapid thermal annealing of silicon layers doped with low-energy high-dose ion implantation  

International Nuclear Information System (INIS)

The model of transient enhanced diffusion of ion-implanted As is formulated and the finite-difference method for numerical solution of the system of equations obtained is developed. The nonuniform distribution of point defects near the interface and more accurate description of arsenic clustering are simultaneously taken into account. Simulation of As diffusion during rapid annealing gives a reasonable agreement with the experimental data. (authors)

2005-09-01

477

Role of mechanical vibration in preventive maintenance programmes  

Energy Technology Data Exchange (ETDEWEB)

Vibration of machinery plays an important role in preventive maintenance programs of machinery. It can be applied in different phases ranging from simple to computerized programs. The advantages of applying machine condition monitoring programs are numerous since vibration measurement and analysis leads to the early detection of component deterioration. The cost, savings and some details of the vibration preventive maintenance program are discussed.

1989-11-01

478

Radiation hazards from medical applications  

International Nuclear Information System (INIS)

An introduction is presented on the radiation hazards connected with biomedical radiography and nuclear medicine. The frequency of radiodiagnostic efforts was rather high in the Netherlands. This was reduced considerably by abolishing the thorax screening of the population. About diagnostic nuclear medicine less can be said because far fewer numerical data are available. An exposition of genetically and somatically significant doses and how to compute them is given. The drawing up of a profit versus risk evaluation for medical applications of ionizing radiations is recommended. (Auth.).

1980-05-31

479

Pumped storage in the future power supply system  

Energy Technology Data Exchange (ETDEWEB)

Pumped storage plants (PSP) supply up to several GW of power and several ten GWh of capacity. Short start-up times and low start-up costs predestine PSP for the control energy market. Grid charges for PSP endanger the further integration of renewable energy and lead to higher electricity supply costs. Therefore, an amendment of legislation is urgently required. Requirements for building large PSP are met at numerous sites in the low mountain ranges of Germany. (orig.)

2010-07-01

480

Progress in lattice QCD  

Energy Technology Data Exchange (ETDEWEB)

After reviewing some of the mathematical foundations and numerical difficulties facing lattice QCD, I review the status of several calculations relevant to experimental high-energy physics. The topics considered are moments of structure functions, which may prove relevant to search for new phenomena at the LHC, and several aspects of flavor physics, which are relevant to understanding CP and flavor violation.

2002-09-30

481

Periodic optimal control with application to pumped storage plants  

Energy Technology Data Exchange (ETDEWEB)

This paper suggests how nonlinear periodic optimal control of a pumped storage plant can be realized. The control problem consists in maximization of the plant benefits over an operational period. An optimal control law is proposed, yielding a bang-off-bang mode of operation. An algorithm for numerical solution of the problem was developed, and its effectiveness was demonstrated by simulation experiments.

1987-04-01

482

Numerical study of the impingement of a supersonic, axisymmetric jet on a flat plate  

International Nuclear Information System (INIS)

A numerical method for studying the flow field of an under-expanded axis-symmetric jet created by a converging-diverging nozzle and impinging on a flat plate is presented. The calculation domain of interest is a region that contains all the features of the jet that leaves the nozzle and impinges onto the plate. Axial symmetry of the domain allows a reduced 2-dimensional model to be used. FLUENT software is utilized to solve the continuity, momentum and energy equations using a coupled implicit scheme. The ideal-gas law is used to determine the gas density along with a k-#epsilon# turbulence model with a special modification to account for compressibility effects. In addition, the temperature dependency of viscosity has been taken into consideration. A number of different modeling techniques are investigated including different approximations to account for the flow inside the nozzle. Performance of non-equilibrium wall functions for near-wall turbulence treatment ...

483

Numerical ray tracing of electrons in different 3D fringing fields of spherical deflectors  

Science.gov (United States)

This paper presents the results of numerical investigations on electron trajectories in different 3D fringing fields of spherical defectors. We start with a chosen set of geometrical values for the electrodes such as radius of curvature, electrode gap, angle between entrance and exit face. We do a first numerical calculation of the spatial potential distribution using a 3D electron optics program based on the finite difference method (FDM). Ray tracing through this potential distribution is then performed using another program, which also gives the potential and the electric field strength along the curved beam path. In the next step we estimate the position and the geometry of the field clamp using Herzog's formulae assuming the entrance of a parallel plate condenser to be a good approximation for the entrance of the spherical deflector in first order. For the consecutive numerical recalculations of the real potential ...

1999-11-01

484

Numerical methods for matrix computations using arrays of processors. Final report, 15 August 1983-15 October 1986  

Energy Technology Data Exchange (ETDEWEB)

The basic objective of this project was to consider a large class of matrix computations with particular emphasis on algorithms that can be implemented on arrays of processors. In particular, methods useful for sparse matrix computations were investigated. These computations arise in a variety of applications such as the solution of partial differential equations by multigrid methods and in the fitting of geodetic data. Some of the methods developed have already found their use on some of the newly developed architectures.

1987-04-30

485

Numerical calculation of the transient response of transmission systems using the natural spline functions, with applications on high-voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

To determine the transient response of linear and time-invariant transmission systems which are only described for discret frequencies, it is possible to find a good functional approximation by means of the generalized impulse method, combined with the most important natural spline-interpolation functions of the first and the third degree. This procedure has been applied to calculate the step response of the transient behaviour of the zero-sequence impedance system of the high voltage transmission line.

1981-10-01

486

Non-uniqueness in conformal formulations of the Einstein constraints  

CERN Document Server

Standard methods in non-linear analysis are used to show that there exists a parabolic branching of solutions of the Lichnerowicz-York equation with an unscaled source. We also apply these methods to the extended conformal thin sandwich formulation and show that if the linearised system develops a kernel solution for sufficiently large initial data then we obtain parabolic solution curves for the conformal factor, lapse and shift identical to those found numerically by Pfeiffer and York. The implications of these results for constrained evolutions are discussed.

2006-01-01

487

New approach to power system stabilizer design  

Energy Technology Data Exchange (ETDEWEB)

A generalized method for the design of excitation control or a power system stabilizer (PSS) based on complex frequency is described. The method selects PSS parameters such that exact assignment of eigenvalues associated with the mechanical modes of oscillation to desired locations is achieved. Numerical examples are used to illustrate the concepts of the proposed new technique.

1985-05-01

488

Modelling of gravity changes in mining areas  

Energy Technology Data Exchange (ETDEWEB)

The numerical modelling of gravity changes resulting from the simultaneous effects of mass relocation and rock deformation is described. The method is supported by FEMMA (Finite Element Method for Multipurpose Applications) software, and has been used for modelling expected gravity changes in a large open pit coal mine in Poland. The results are in good agreement with conventional calculations of gravity changes for a simple geometry of relocated mass. 10 refs., 6 figs., 2 tabs.

1995-10-01

489

Ion-Track Membranes and Their Use in Biological and Medical Applications  

International Nuclear Information System (INIS)

This report is a brief review of biological and medical applications of ion-track membranes. The review aims at informing nuclear physicists about alternative (i.e. non-fundamental-science) use of heavy ion accelerators such as production of micro- and nano-porous materials. The ion-track membranes produced this way are employed in life sciences and numerous technological applications. The author focuses on recent results from the Flerov laboratory in co-operation with other scientific institutions and industrial partners.

2007-05-22

490

Fluctuations of the energy of Stokes pulses of resonance coherent SRS  

International Nuclear Information System (INIS)

An analytic solution is obtained for the equations of resonance coherent SRS by neglecting the population of the final level of the Raman transition for the systems with the active-medium length that is smaller than the wavelength of the incident light. For the extended systems, a numerical solution is obtained. The energy distribution of the Stokes pulses is found. The large-scale (about 100%) fluctuations of the Stokes radiation energy were observed in the case of unsaturated amplified spontaneous emission. (nonlinear optical phenomena)

2000-11-30

491

Estimation of the mean distance of closest approach of some heavy metal ions in aqueous solutions: some experimental and theoretical calculations  

British Library Electronic Table of Contents (United Kingdom)

The estimation of numerical values of the mean distance of closest approach of ions, a, of heavy metal ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.

2011-01-01

492

Effect of polychlorinated biphenyls (Aroclor 1254) on rhythmic pituitary-adrenal function. [Rats  

Energy Technology Data Exchange (ETDEWEB)

Numerous studies have documented the general toxicity of the polychlorinated biphenyls (PCBs) and a sizeable literature has accumulated concerning the toxic effects of PCBs on a variety of homeostatic systems. However, current information regarding the effects of PCBs on rhythmic endocrine function is quite limited. Thus, the present study was undertaken to determine whether circadian periodicity in pituitary-adrenal function is affected by exposure to PCBs.

1983-09-01

493

Dimension reduction in fluid dynamics equations  

British Library Electronic Table of Contents (United Kingdom)

A method for transforming the Euler and Navier-Stokes equations and a complete system of fluid dynamics equations in three dimensions to a closed system on any moving surface is proposed. As a result, for an arbitrary geometric configuration, the dimension of the equations is reduced by one, which makes them convenient for numerical simulation. The general principles of the method are described, and verifying examples are presented.

2011-01-01

494

Climates of the oceans  

Energy Technology Data Exchange (ETDEWEB)

''Climates of the Oceans'' deals with the atmosphere over the world oceans and provides a treatment not only of the climatic elements such as temperature, pressure, wind, precipitation etc., but also of the circulation of the atmosphere and its changes throughout the year. The connection between sea and overlying air is examined through studies of the water and heat balance. Numerous maps and tables illustrate the elements and their fluctuations over the water and on islands and coasts.

1984-01-01

495

Calculation of atomic spontaneous emission rate in 1D finite photonic crystal with defects  

CERN Document Server

We derive the expression for spontaneous emission rate in finite one-dimensional photonic crystal with arbitrary defects using the effective resonator model to describe electromagnetic field distributions in the structure. We obtain explicit formulas for contributions of different types of modes, i.e. radiation, substrate and guided modes. Formal calculations are illustrated with a few numerical examples, which demonstrate that the application of effective resonator model simplifies interpretation of results.

2009-01-01

496

Calculation of 3-D electrical field distribution around technical devices in the vicinity of high voltage transmission lines  

Energy Technology Data Exchange (ETDEWEB)

The influence that electromagnetic fields have on mechanical and electronic equipment was discussed. A three dimensional numerical simulation model of electric fields around high voltage power transmission lines was described. 4 refs., 1 tab., 5 figs.

1997-12-31

497

Calculation of 3-D electrical field distribution around technical devices in the vicinity of high voltage transmission lines  

International Nuclear Information System (INIS)

The influence that electromagnetic fields have on mechanical and electronic equipment was discussed. A three dimensional numerical simulation model of electric fields around high voltage power transmission lines was described. 4 refs., 1 tab., 5 figs.

1997-08-24

498

Analytical determination of the dimensions and evolution with current of the ion-emitting jet in liquid-metal ion sources  

Energy Technology Data Exchange (ETDEWEB)

The apex dimensions and length are calculated as a function of current for the ion-emitting jet in liquid-metal ion sources (LMIS). The results agree well with observations. Since the final expressions are analytical, they give more insight into the fundamental mechanisms involved than do numerical calculations. Some implications of the model are discussed concerning focused ion beam (FIB) systems employing LMIS. (author).

1991-12-14

499

Analysis of current diffusive ballooning mode in tokamaks  

Energy Technology Data Exchange (ETDEWEB)

The effect of finite gyroradius on the current diffusive ballooning mode is examined. Starting from the reduced MHD equations including turbulent transports, coupling with drift motion and finite gyroradius effect of ions, we derive a ballooning mode equation with complex transport coefficients. The eigenfrequency, saturation level and thermal diffusivity are evaluated numerically from the marginal stability condition. Preliminary results of their parameter dependence is presented. (author)

1999-12-01

500

A Combinatorial Interplay Among the 1-Aminocyclopropane-1-Carboxylate Isoforms Regulates Ethylene Biosynthesis in Arabidopsis thaliana  

UK PubMed Central (United Kingdom)

Ethylene (C2H4) is a unique plant-signaling molecule that regulates numerous developmental processes. The key enzyme in the two-step biosynthetic pathway of ethylene is 1-aminocyclopropane-1-carboxylate...Full Text Available

2009-11-01