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1

Non-commutative space and Chan-Paton algebra in open string field algebra  

Energy Technology Data Exchange (ETDEWEB)

There are several equivalent descriptions for constant B-field background of open string. The background can be interpreted as constant B-field as well as constant gauge field strength or infinitely many D-branes with non-commuting Chan-Paton matrices. In this article, the equivalence of these open string theories is studied in Witten's cubic open string field theory. Through the map between these equivalent descriptions, both algebra of non-commutative coordinates as well as Chan-Paton matrix algebra are identified with subalgebras of open string field algebra. (author)

2002-09-23

2

Extracellular Signaling through the Microenvironment: A Hypothesis Relating Carcinogenesis, Bystander Effects, and ...  

Science.gov (United States)

... Extracellular Signaling through the Microenvironment: A Hypothesis Relating Carcinogenesis, Bystander Effects, and Genomic InstabilityMary Helen Barcellos-Hoff1a ... ...

3

Electrical impact of Mt. St. Helens  

Energy Technology Data Exchange (ETDEWEB)

Ash fallout from the Mount Saint Helens eruptions affected high-voltage transmission in a four-state area as volatile gases caused conductivity changes and corrosion. The Bonneville Power Authority (BPA) found that it was possible to maintain electric service except for a few short, localized outages. Cleaning ash from transformers and substations was the first priority. Tests were underway within 48 hours to determine ash characteristics and cleaning procedures. A summary to what happened and what was learned is presented in two lists. (DCK)

1981-08-01

4

Comparison of Mount Saint Helens volcanic eruption to a nuclear explosion. Technical note  

Energy Technology Data Exchange (ETDEWEB)

The phenomena and effects of airblast, ground shock, thermal radiation, cratering and ejecta, and debris cloud and deposition from the eruption of Mt. St. Helens were compared to those that would result from a nuclear explosion to determine if phenomena or effects were analogous and thus might provide useful data for military nuclear weapon effects studies. It is concluded that the phenomena are not analogous. In particular, airblast destruction was caused by clouds of ash driven by subsonic winds, rather than by a supersonic shock wave that would be the damage mechanism of a nuclear explosion. Because of the lack of analogy between the eruption and nuclear explosion phenomena, it appears questionable that any of the effects are analogous; therefore, it is unlikely that anything more of military interest can be gained from studying the effects of the eruption. However, key contacts for further information on the eruption and the associated research studies are ...

1981-01-01

5

Volatiles of Mount St. Helens and their origins  

Energy Technology Data Exchange (ETDEWEB)

Analyses have been made of gases in clouds apparently emanating from Mount Saint Helens. Despite appearances, most of the water in these clouds does not issue from the volcano. Even directly above a large fumarole deltaD and delta/sup 10/O data indicate that only half the water can come from the volcano. Isotopic and chemical evidence also shows the steam in the volcano (-33.0 per mol deltaD) from which a condensate of 0.2 N HCl was obtained is not a major cause of the explosions. The steam in the volcano is derived from a metamorphic brine in the underlying Tertiary meta andesite. The gas that caused the explosive eruptions is carbon dioxide.

1984-09-01

6

Particulate kinematic simulations of debris avalanches: interpretation of deposits and landslide seismic signals of Mount Saint Helens, 1980 May 18:  

British Library Electronic Table of Contents (United Kingdom)

SUMMARY We construct a new class of granular landslide models in which avalanches are simulated with large numbers of independent particles moving under the influence of topographically derived gravitational and centripetal acceleration. Concurrently, the particles suffer deceleration due to basal and dynamic friction. The novel aspect of the calculation is that complex particle-to-particle interactions, fluctuating basal contacts, and unresolved topographic roughness within and below the deforming flow are mimicked by random perturbations in along-track and cross-slope acceleration. We apply the method to the 1980 May 18 Mount Saint Helens debris avalanche by constraining the initial geometry and structure of the slide mass from geological data, and the initial failure sequence from eyewi...

2006-01-01

7

Intensity of auger-emission of silicon from binary compounds in the ion auger spectroscopy  

International Nuclear Information System (INIS)

Auger-electron emission from different silicides has been studied for 4 and 10 keV Ar ion excitation. The intensity of the SiLMM Auger line changes significantly with channing concentration and atomic number of the metal-parthner. The experimental results can be explained in terms of a simple model based on the probability of Si-Si collision symmetric cascade in these binary compounds.

8

Successional Change in Phosphorus Stoichiometry Explains the Inverse Relationship between Herbivory and Lupin Density on Mount St. Helens  

UK PubMed Central (United Kingdom)

BackgroundThe average nitrogen-to-phosphorus ratio (N∶P) of insect herbivores is less than that of leaves, suggesting that P may mediate plant-insect interactions more often...Full Text Available

9

Wolsong 2,3 and 4 fuel channel analysis during a large break loss of coolant accident with loss of ECCS injection  

International Nuclear Information System (INIS)

Wolsong 2,3 and 4 fuel channel analysis during a large break loss of coolant accident with loss of ECCS injection (LOCA/LOECC) is performed to obtain the heat load to moderator. Because the single channel analysis requires the establishment of the safety codes and their input decks, the present study follows the same safety analysis methodology found in FSAR of Wolsong 2,3 and 4. From this work we obtain the safety tools such as CATHENA MOD3.5b/Rev.1 and CHAN-II/A MOD2 codes, and their code modeling in a form of code input deck. The analysis consists of two parts: front-end (blowdown period) and back-end. For the front-end analysis the fuel and pressure tube (PT) temperatures, and PT circumferential strains at the end of front-end as well as fuel channel depressurization are calculated using CATHENA code and used as initial and boundary conditions for back-end analysis. The back-end period under the conditions of prolonged low steam flow is analyzed by ...

2002-10-01

10

Acoustic band gaps in arrays of neutral inclusions  

British Library Electronic Table of Contents (United Kingdom)

We analyse numerically the acoustic stop band properties of an array of orthotropic coated cylinders whose elastic parameters are deduced from a geometric transform [H. Chen, C.T. Chan, Acoustic cloaking in three dimensions using acoustic metamaterials, Appl. Phys. Lett. 91 (2007) 183518]. We find that whereas a single coated inclusion is acoustically neutral at any frequency, an array of them might display some stop bands. More precisely, an array of freely vibrating coated voids is always neutral, whereas an array of clamped coated inclusions might display a zero frequency stop band. Interestingly, an array of radially symmetric coated inclusions behaves as local Helmholtz resonators, for which the eigenfield within each cloak is obtained in closed form, leading to a frequency estimate a...

2010-01-01

11

Theoretical nuclear physics. Final report  

Energy Technology Data Exchange (ETDEWEB)

As the three-year period FY93-FY96 ended, there were six senior investigators on the grant full-time: Bulgac, Henley, Miller, Savage, van Kolck and Wilets. This represents an increase of two members from the previous three-year period, achieved with only a two percent increase over the budget for FY90-FY93. In addition, the permanent staff of the Institute for Nuclear Theory (George Bertsch, Wick Haxton, and David Kaplan) continued to be intimately associated with our physics research efforts. Aurel Bulgac joined the Group in September, 1993 as an assistant professor, with promotion requested by the Department and College of Arts and Sciences by September, 1997. Martin Savage, who was at Carnegie-Mellon University, jointed the Physics Department in September, 1996. U. van Kolck continued as research assistant professor, and we were supporting one postdoctoral research associate, Vesteinn Thorssen, who joined us in September, 1995. Seven graduate students were being supported by the ...

1997-05-01

12

Development of a Simple Scheme for Prediction of Flame Acceleration and DDT  

International Nuclear Information System (INIS)

Hydrogen combustion phenomenology during severe accidents in nuclear power plants has been a safety issue. Especially, flame acceleration (FA) and Deflagration-to-Detonation Transition (DDT) are important because of their possible destructive impact on the containment or plant systems in it. Accordingly, it is the design goal to avoid FA and DDT for the hydrogen mitigation system. As a result from extensive effort dedicated to resolve the hydrogen issue, compiled information on the FA and DDT has been provided by the NEA. The FA criterion was suggested in terms of the mixture expansion ratio ? , and the criterion for onset of DDT was based on the greatness of the geometrical size of the reactive system compared with the detonation cell width ? of the average mixture composition. The DDT onset criterion reflects the current state of knowledge based on the experimental database; however, the criterion is not sufficient but a necessary condition. Therefore, it should be noted that ...

2010-10-01

13

Adaptive Waveform Correlation Detectors for Arrays: Algorithms for Autonomous Calibration  

Energy Technology Data Exchange (ETDEWEB)

Waveform correlation detectors compare a signal template with successive windows of a continuous data stream and report a detection when the correlation coefficient, or some comparable detection statistic, exceeds a specified threshold. Since correlation detectors exploit the fine structure of the full waveform, they are exquisitely sensitive when compared to power (STA/LTA) detectors. The drawback of correlation detectors is that they require complete knowledge of the signal to be detected, which limits such methods to instances of seismicity in which a very similar signal has already been observed by every station used. Such instances include earthquake swarms, aftershock sequences, repeating industrial seismicity, and many other forms of controlled explosions. The reduction in the detection threshold is even greater when the techniques are applied to arrays since stacking can be performed on the individual channel correlation traces to achieve significant array gain. In previous ...

2009-07-23