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University of New Hampshire

1994

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Articles 1 - 30 of 46

Full-Text Articles in Physical Sciences and Mathematics

Viewing A Graph In A Virtual Reality Display Is Three Times As Good As A 2d Diagram, Colin Ware, Glenn Franck Oct 1994

Viewing A Graph In A Virtual Reality Display Is Three Times As Good As A 2d Diagram, Colin Ware, Glenn Franck

Center for Coastal and Ocean Mapping

An experiment is reported which tests whether network information is more effectively displayed in a three dimensional space than in a two dimensional space. The experimental task is to trace a path in a network and the experiment is carried out in 2D, in a 3D stereo view, in a 2D view with head coupled perspective, and in a 3D stereo view with head coupled perspective; this last condition creates a localized virtual reality display. The results show that the motion parallax obtained from the head coupling of perspective is more important than stereopsis in revealing structural information. Overall the …

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Representing Nodes And Arcs In 3d Networks, Glenn Franck, Colin Ware Oct 1994

Representing Nodes And Arcs In 3d Networks, Glenn Franck, Colin Ware

Center for Coastal and Ocean Mapping

This paper introduces six graphical principles for 30 network displays. These are justified with examples from GraphVisualizer3D, a system developed by the authors to investigate the problems of 30 visualization of information networks. GraphVisualizer3D enables the exploration of sulface color, surface texture, object shape, arc shape and labeling conventions.

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Table Of Contents Volume Five, Number Four, Fall 1994, Risk Editorial Board Sep 1994

Table Of Contents Volume Five, Number Four, Fall 1994, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

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Comparison Of Environmental Risk Provisions In The 103d Congress, Linda-Jo Schierow Sep 1994

Comparison Of Environmental Risk Provisions In The 103d Congress, Linda-Jo Schierow

RISK: Health, Safety & Environment (1990-2002)

Dr. Schierow, an Analyst in Environmental Policy with the Congressional Research Service, presents a tabulated summary of comparable provisions in several bills with special attention to the Risk Assessment Improvement Act of 1994.

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Preferences For Exposure Control Of Power-Frequency Fields Among Lay Opinion Leaders, Ann Bostrom, M. Granger Morgan, Jack Adams, Indira Nair Sep 1994

Preferences For Exposure Control Of Power-Frequency Fields Among Lay Opinion Leaders, Ann Bostrom, M. Granger Morgan, Jack Adams, Indira Nair

RISK: Health, Safety & Environment (1990-2002)

The authors report on surveys, differing according to focus on remedial costs, of Pittsburgh-area adults indicating beliefs about possible health effects of electromagnetic fields and the acceptability of options for reducing or eliminating the potential impact.

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Trace Substances, Science And Law: Perspectives From The Social Sciences, James F. Short Jr. Sep 1994

Trace Substances, Science And Law: Perspectives From The Social Sciences, James F. Short Jr.

RISK: Health, Safety & Environment (1990-2002)

Using advances in analytical technology as a point of departure, Dr. Short reviews what social science research reveals about perceptions, decision making processes and behaviors of organizations and individuals who try to cope with risk and uncertainty.

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Review Of: Gerald Holton, Science And Anti-Science, Russell W. Binns Jr. Sep 1994

Review Of: Gerald Holton, Science And Anti-Science, Russell W. Binns Jr.

RISK: Health, Safety & Environment (1990-2002)

Review of : Gerald Holton, Science and Anti-Science (Harvard University Press 1993). LC 92-272; ISBN 0-674-79298-X. Index, notes, preface, sources. [176 pp. Cloth $24.95. 79 Garden St., Cambridge MA 02138.]

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Five Year Cumulative Index: Book Reviews & Essays By Title, Risk Editorial Board Sep 1994

Five Year Cumulative Index: Book Reviews & Essays By Title, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

A five year cumulative index of book reviews and essays by title for the journal RISK.

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Review Of: Ann Rappaport, Development And Transfer Of Pollution Prevention Technology, Kristina M. Jahns Sep 1994

Review Of: Ann Rappaport, Development And Transfer Of Pollution Prevention Technology, Kristina M. Jahns

RISK: Health, Safety & Environment (1990-2002)

Review of: Ann Rappaport, Development and Transfer of Pollution Prevention Technology (Quorum Books 1993). Appendices, bibliographical references, figures, index, preface, tables. LC 93-292; ISBN 0-89930-816-3 [203 pp. Cloth $55.00. 88 Post Road West, Westport CT 06881.]

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Five Year Cumulative Index: Articles And Comments By Title, Risk Editorial Board Sep 1994

Five Year Cumulative Index: Articles And Comments By Title, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

A five year cumulative index of articles and comments by title for the journal RISK.

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Temporal Alternation Between Light- And Nutrient-Limitation Of Phytoplankton Production In A Coastal Plain Estuary., Jonathan Pennock, Jonathan H. Sharp Aug 1994

Temporal Alternation Between Light- And Nutrient-Limitation Of Phytoplankton Production In A Coastal Plain Estuary., Jonathan Pennock, Jonathan H. Sharp

School of Marine Science and Ocean Engineering

ABSTRACT: The potential for Light- and nutrient-limitation of phytoplankton production was examined in the Delaware Estuary, USA, by combining a hierarchy of expenmental approaches including smallscale bioassay experiments, ecosystem-level analysis of nutrient concentration and stoichiometric ratios, and light-limitation modeling. Light was found to be the predominate regulator of phytoplankton growth throughout the estuary during the winter period as a result of high turbidity and a wellmixed water column. However, during late spring, phosphorus (P) was found to limit growth. This observation was confirmed at each of the experimental levels, and was related to several factors, including elevated input ratios (230:l) …

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Soluble Acidic Species In Air And Snow At Summit, Greenland, Jack E. Dibb, R. Talbot, M H. Bergin Jul 1994

Soluble Acidic Species In Air And Snow At Summit, Greenland, Jack E. Dibb, R. Talbot, M H. Bergin

Earth Sciences

Simultaneous measurements of the concentrations of soluble acidic species in the gas, aerosol and snow phases at Summit, Greenland were made during summer 1993. Mean concentrations of gas phase HCOOH, CH3COOH, and HNO3 (49±28, 32±17 and 0.9±0.6 nmol m−3 STP, respectively) exceeded the concentrations of aerosol-associated HCOO−, CH3COO−, and NO3−by 1–3 orders of magnitude. On average, SO2 concentrations (0.9±0.6 nmol m−3 STP) were approximately 1/3 those of aerosol SO4=, but this ratio varied widely due largely to changes in the concentration of …

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Estimation Of Stratospheric Input To The Arctic Troposphere: 7be And 10be In Aerosols At Alert, Canada, Jack E. Dibb, David Meeker, R C. Finkel, J Southon, Marc W. Caffee, Leonard A. Barrie Jun 1994

Estimation Of Stratospheric Input To The Arctic Troposphere: 7be And 10be In Aerosols At Alert, Canada, Jack E. Dibb, David Meeker, R C. Finkel, J Southon, Marc W. Caffee, Leonard A. Barrie

Earth Sciences

Concentrations of 7Be and 210Pb in 2 years of weekly high-volume aerosol samples collected at Alert, Northwest Territories, Canada, showed pronounced seasonal variations. We observed a broad winter peak in 210Pb concentration and a spring peak in 7Be. These peaks were similar in magnitude and duration to previously reported results for a number of stations in the Arctic Basin. Beryllium 10 concentrations (determined only during the first year of this study) were well correlated with those of 7Be; the atom ratio 10Be/7Be was nearly constant at 2.2 throughout the year. This relatively high value of 10Be/7Be indicates that the stratosphere …

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Reporting On Risk: Who Decides What's News?, William Lanouette Jun 1994

Reporting On Risk: Who Decides What's News?, William Lanouette

RISK: Health, Safety & Environment (1990-2002)

Dr. Lanouette argues that risks alone do not command national media attention; their implications must first be framed by broader national issues.

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Historical Notes On German Press Coverage Of Technology, Hans Mathias Kepplinger Jun 1994

Historical Notes On German Press Coverage Of Technology, Hans Mathias Kepplinger

RISK: Health, Safety & Environment (1990-2002)

Professor Kepplinger accounts for increased negativism in German media coverage of technology by pointing to changes in journalists' role definitions and attitudes.

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The Media, Risk Assessment And Numbers: They Don't Add Up, Sharon M. Friedman Jun 1994

The Media, Risk Assessment And Numbers: They Don't Add Up, Sharon M. Friedman

RISK: Health, Safety & Environment (1990-2002)

Professor Friedman argues that, for risks to be reported accurately, journalism educators must help their students understand science, numbers and statistics.

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Mass Media As An Information Channel And Public Arena, Hans Peter Peters Jun 1994

Mass Media As An Information Channel And Public Arena, Hans Peter Peters

RISK: Health, Safety & Environment (1990-2002)

Professor Peters argues that several functions of mass media compete and that attempts to improve risk coverage must avoid optimizing one at the expense of others.

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Table Of Contents Volume Five, Number Three, Summer 1994, Risk Editorial Board Jun 1994

Table Of Contents Volume Five, Number Three, Summer 1994, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

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Mass Media And Environmental Risk: Seven Principles, Peter M. Sandman Jun 1994

Mass Media And Environmental Risk: Seven Principles, Peter M. Sandman

RISK: Health, Safety & Environment (1990-2002)

Dr. Sandman suggests that, when spokespersons for risk sources are inept in conveying their messages, they and we pay heavily for their mistakes.

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Comptel Imaging Of The Galactic Disk And The Separation Of Diffuse Emission And Point Sources, H Bloemen, W Hermsen, B Swanenburg, C De Vries, R Diehl, V. Schonfelder, H Steinle, A W. Strong, A Connors, Mark L. Mcconnell, D Morris, G Stacy, K Bennett, C Winkler Jun 1994

Comptel Imaging Of The Galactic Disk And The Separation Of Diffuse Emission And Point Sources, H Bloemen, W Hermsen, B Swanenburg, C De Vries, R Diehl, V. Schonfelder, H Steinle, A W. Strong, A Connors, Mark L. Mcconnell, D Morris, G Stacy, K Bennett, C Winkler

Physics & Astronomy

The first MeV image of the inner Galaxy obtained with the COMPTEL telescope aboard the Compton Gamma-Ray Observatory shows a structured ridge of emisssion along the Galactic equator which probably consists of diffuse radiation and unresolved discrete sources. The intensity distribution of this ridge distinctly differs from the expected distribution for a simple model of the diffuse radiation. Most remarkable are the observed excursions out of the disk, which may hint at the presence of gamma-ray point sources located several degrees away from the mid-plane, but a diffuse origin cannot be excluded. If these are indeed discrete sources, a substantial …

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Application Of A Maximum Likelihood Processor To Acoustic Backscatter For The Estimation Of Seafloor Roughness Parameters, Zoi-Heleni Michalopoulou, Christian De Moustier May 1994

Application Of A Maximum Likelihood Processor To Acoustic Backscatter For The Estimation Of Seafloor Roughness Parameters, Zoi-Heleni Michalopoulou, Christian De Moustier

Center for Coastal and Ocean Mapping

Maximum likelihood (ML) estimation is used to extract seafloor roughness parameters from records of acoustic backscatter. The method relies on the Helmholtz–Kirchhoff approximation under the assumption of a power‐law roughness spectrum and on the statistical modeling of bottom reverberation. The result is a globally optimum, highly automated technique that is a useful tool in the context of seafloor classification via remote acoustic sensing. The general geometry of the Sea Beam bathymetric system is incorporated into the design of the ML processor in order to make it applicable to real acoustic data collected by this system. The processor is initially tested …

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Observations Of Gamma-Ray Bursts By Comptel, L O. Hanlon, K Bennett, W Collmar, A Connors, R Diehl, R Van Dijk, J Greiner, J W. Den Herder, W Hermsen, R M. Kippen, L Kuiper, Mark L. Mcconnell, James M. Ryan, V. Schonfelder, H Steinle, A W. Strong, M Varendorff, C Winkler May 1994

Observations Of Gamma-Ray Bursts By Comptel, L O. Hanlon, K Bennett, W Collmar, A Connors, R Diehl, R Van Dijk, J Greiner, J W. Den Herder, W Hermsen, R M. Kippen, L Kuiper, Mark L. Mcconnell, James M. Ryan, V. Schonfelder, H Steinle, A W. Strong, M Varendorff, C Winkler

Physics & Astronomy

During the first year of operation, 22 cosmic gamma-ray bursts were detected within the field of view of the COMPTEL instrument on board the Compton Gamma Ray Observatory. Spectra and time histories for the strongest of these bursts have been obtained from both the main instrument (0.75-30 MeV) and the burst modules (0.3-10 MeV). The deconvolved photon spectra for the majority of bursts are fit by a single power law model with spectral index between -1.6 and -2.8. One strong burst, GRB 910814, exhibited significant curvature and could not be fit by a single power law model. A broken power …

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Observations Of Cygnus X-1 Comptel During 1991, Mark L. Mcconnell, D J. Forrest, James M. Ryan, W Collmar, V. Schonfelder, H Steinle, A W. Strong, R Van Dijk, W Hermsen, K Bennett Apr 1994

Observations Of Cygnus X-1 Comptel During 1991, Mark L. Mcconnell, D J. Forrest, James M. Ryan, W Collmar, V. Schonfelder, H Steinle, A W. Strong, R Van Dijk, W Hermsen, K Bennett

Physics & Astronomy

The Compton Telescope (COMPTEL) experiment on the Compton Gamma-Ray Observatory (CGRO) has observed the Cygnus region on two occasions during the first (sky survey) phase of its mission. These data represent the most sensitive observations to date of Cygnus X-1 in the 0.75-30 MeV range. The observations in 1991 June and August both showed evidence for emission in the 0.75-2 MeV energy range. The flux level was larger by about a factor of 2 during the August observation. The spectral data were analyzed in the context of a Wien spectral model (the high-energy limit of the Sunyaev-Titarchuk Comptonization spectrum). Fits …

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Table Of Contents Volume Five, Number Two, Spring 1994, Risk Editorial Board Mar 1994

Table Of Contents Volume Five, Number Two, Spring 1994, Risk Editorial Board

RISK: Health, Safety & Environment (1990-2002)

Table of contents for the journal RISK: Health, Safety & Environment (ISSN: 1073-8673)

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Comptel Measurements Of The Gamma-Ray Burst Grb 930131, James M. Ryan, K Bennett, W Collmar, A Connors, Gerald J. Fishman, J Greiner, L O. Hanlon, W Hermsen, R M. Kippen, C Kouveliotou, L Kuiper, G G. Lichti, John R. Macri, J. Mattox, Mark L. Mcconnell, B Mcnamara, C Meegan, V. Schonfelder, R Vandijk, M Varendorff, W Webber, C Winkler Feb 1994

Comptel Measurements Of The Gamma-Ray Burst Grb 930131, James M. Ryan, K Bennett, W Collmar, A Connors, Gerald J. Fishman, J Greiner, L O. Hanlon, W Hermsen, R M. Kippen, C Kouveliotou, L Kuiper, G G. Lichti, John R. Macri, J. Mattox, Mark L. Mcconnell, B Mcnamara, C Meegan, V. Schonfelder, R Vandijk, M Varendorff, W Webber, C Winkler

Physics & Astronomy

On 1993 January 31 at 1857:12 Universal Time (UT), the Imaging Compton Telescope COMPTEL onboard the Compton Gamma Ray Observatory (CGRO) detected the cosmic gamma-ray burst GRB 930131. COMPTEL's MeV imaging capability was employed to locate the source to better than 2 deg (1 sigma error radius) within 7 hr of the event, initiating a world-wide search for an optical and radio counterpart. The maximum likelihood position of the burst from the COMPTEL data is alpha2000 = 12h 18m, delta2000 = -9 deg 42 min, consistent with independent CGRO-Burst and Transient Source Experiment (CGRO-BATSE) and Energetic Gamma Ray …

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Sulfate And Msa In The Air And Snow On The Greenland Ice Sheet, J L. Jaffrezo, C Davidson, M Legrand, Jack E. Dibb Jan 1994

Sulfate And Msa In The Air And Snow On The Greenland Ice Sheet, J L. Jaffrezo, C Davidson, M Legrand, Jack E. Dibb

Earth Sciences

Sulfate and methanesulfonic acid (MSA) concentrations in aerosol, surface snow, and snowpit samples have been measured at two sites on the Greenland Ice Sheet. Seasonal variations of the concentrations observed for these chemical species in the atmosphere are reproduced in the surface snow and preserved in the snowpit sequence. The amplitude of the variations over a year are smaller in the snow than in the air, but the ratios of the concentrations are comparable. The seasonal variations for sulfate are different at the altitude of the Ice Sheet compared to those observed at sea level, with low concentrations in winter …

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An Overview Of Solar Flare Results From Comptel, Mark L. Mcconnell Jan 1994

An Overview Of Solar Flare Results From Comptel, Mark L. Mcconnell

Space Science Center

The COMPTEL experiment on the Compton Gamma Ray Observatory (CGRO) has been operating in orbit since April of 1991. During that time, COMPTEL has observed several large flares, the most notable of which were several X‐class flares which took place in June of 1991. As a solar instrument, COMPTEL has the capability to measure solar flare radiation in two parallel observing modes. In its telescope mode, COMPTEL is capable of measuring both solar flare photons (in the 0.75–30 MeV range) and solar flare neutrons (in the 20–150 MeV range) using the double scatter technique with a field‐of‐view of ∼1 steradian. …

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First Results Of The Batse/Comptel/Nmsu Rapid Burst Response Campaign, R M. Kippen, A Connors, John R. Macri, Mark L. Mcconnell, James M. Ryan, W Collmar, J Greiner, V Schonfelder, M Varendorff, Gerald J. Fishman, C Meegan, C Kouveliotou, B Mcnamara, T Harrison, W Hermsen, L Kuiper, K Bennett, L O. Hanlon, C Winkler Jan 1994

First Results Of The Batse/Comptel/Nmsu Rapid Burst Response Campaign, R M. Kippen, A Connors, John R. Macri, Mark L. Mcconnell, James M. Ryan, W Collmar, J Greiner, V Schonfelder, M Varendorff, Gerald J. Fishman, C Meegan, C Kouveliotou, B Mcnamara, T Harrison, W Hermsen, L Kuiper, K Bennett, L O. Hanlon, C Winkler

Space Science Center

The Imaging Compton Telescope (COMPTEL) on board the Compton Gamma Ray Observatory regularly observes gamma‐ray bursts which occur inside the instrument’s ∼1 sr field‐of‐view. COMPTEL images bursts in the 0.75–30 MeV energy range with a typical location accuracy of 1–3 degrees, depending on burst strength, position, duration, and spectrum. COMPTEL’s imaging capability has been exploited in order to search for fading gamma‐ray burst counterparts at other wavelengths through the establishment of a BATSE/COMPTEL/NMSU rapid burst response campaign. This campaign utilizes near real‐time identification and preliminary burst location by BATSE, accelerated COMPTEL imaging, and a world‐wide network of observers to search …

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Empirical Modeling Of The Quiet Time Nightside Magnetosphere, A. T. Y. Lui, Harlan E. Spence, D. P. Stern Jan 1994

Empirical Modeling Of The Quiet Time Nightside Magnetosphere, A. T. Y. Lui, Harlan E. Spence, D. P. Stern

Physics & Astronomy

Empirical modeling of plasma pressure and magnetic field for the quiet time nightside magnetosphere is investigated. Two models are constructed for this study. One model, referred to here as T89R, is basically the magnetic field model of Tsyganenko (1989) but is modified by the addition of an inner eastward ring current at a radial distance of ∼3 RE as suggested by observation. The other is a combination of the T89R model and the long version of the magnetic field model of Tsyganenko (1987) such that the former dominates the magnetic field in the inner magnetosphere, whereas the latter prevails in …

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137cs Gamma-Ray Detection At Summit, Greenland, P. P. Dunphy, Jack E. Dibb Jan 1994

137cs Gamma-Ray Detection At Summit, Greenland, P. P. Dunphy, Jack E. Dibb

Earth Sciences

Global fall-out from atmospheric testing of thermonuclear weapons produced horizon markers corresponding to the initiation of testing in 1953 and the maximum fall-out in 1963. The radioactive isotope 137Cs associated with these events has a half-life of 30.2 years. Therefore, with the appropriate radiation detectors, this fall-out can be used as a long-term temporal indicator in glaciers and snowpack. A prototype γ-ray detector system was successfully tested and was used to make in-situ measurements of the 137Cs marker in a borehole at Summit, Greenland. The system consisted of a 7.6 cm by 7.6 cm NaI (Tl) scintillation crystal/photomultiplier detector, commercial …

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