Physical Sciences and Mathematics Commons^™

Specification Of Jecp/Holz, An Interactive Computer Program For Simulation Of Holz Pattern, Xingzhong Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

1. Purpose of the program 2. Graphic user interface and program design 3. Formulas for calculating the positions of the HOLZ lines 4. System requirement 5. Installation and user instruction 6. How to contact the author 7. References

1. Purpose of the program JECP/HOLZ (Li, 2005a) is one computer program in the Java Electron Crystallography Package (JECP), which is designed and written by Dr. XingZhong Li. The package is developed for quantitative electron diffraction and image processing purpose, JECP/HOLZ is an interactive program for simulation of the higher-order Laue zone (HOLZ) lines using kinematical approximation and a first-order dynamic correction. …

Tr-2005002: The Basic Intuitionistic Logic Of Proofs, Sergei Artemov, Rosalie Iemhoff

Computer Science Technical Reports

No abstract provided.

Tr-2005003: Making Knowledge Explicit: How Hard It Is, Vladimir Brezhnev, Roman Kuznets

Computer Science Technical Reports

No abstract provided.

Tr-2005004: Basic Systems Of Epistemic Logic With Justification, Sergei Artemov, Elena Nogina

Computer Science Technical Reports

No abstract provided.

Tr-2005005: Geometric Interpretation And Spherical Property Of The 2-D Poisson Kernel, Sergei Artamoshin

Computer Science Technical Reports

No abstract provided.

Tr-2005009: Additive Preconditioning In Matrix Computations, Victor Y. Pan, Brian Murphy, Rhys Eric Rosholt

Computer Science Technical Reports

No abstract provided.

Tr-2005012: Propositional Games With Explicit Strategies, Bryan Renne

Computer Science Technical Reports

No abstract provided.

Tr-2005010: Multi-Hop Probing Asymptotics In Available Bandwidth Estimation: Stochastic Analysis, Xiliang Liu, Kaliappa Ravindran, Dmitri Loguinov

Computer Science Technical Reports

No abstract provided.

Tr-2005013: Typing In Reflective Combinatory Logic, Nikolai Krupski

Computer Science Technical Reports

No abstract provided.

Response To "Kinetic And Mechanistic Studies Of The Recombination Of Oh With No2: Vibrational Deactivation, Isotopic Scrambling And Product Isomer Branching Ratios", J. Stutz, A. R. Ravishankara, J. A. Pyle, A. Tuck, M. J. Evans, H. Herrmann, M. P. Chipperfield, R. Zellner, H. Roscoe, D. E. Shallcross, R. A. Cox, P. S. Monks, S. R. Arnold, D. S. Stevenson, D. E. Heard, J. J. Remedios, R. P. Wayne, E. A. Cohen, T. Brauers, A. J. Orr-Ewing, M. A. Blitz, L. Wang, G. Duxbury, T. Dibble, C. A. Taatjes, W. Eisfeld, P. W. Seakins, A. Kovács, S. Dóbé, E. Farkas, T. Ingham, D. Rowley, C. E. Kolb, Thomas Alex Stephenson, A. J. Hynes, N. M. Donahue, I. W. M. Smith, D. Self, D. J. Donaldson

Chemistry & Biochemistry Faculty Works

No abstract provided.

Sulfoxides As An Intramolecular Sulfenylating Agent For Indoles And Diverse Applications Of The Sulfide-Sulfoxide Redox Cycle In Organic Chemistry, Parag V. Jog

Dissertations, Master's Theses and Master's Reports - Open

This dissertation involves study of various aspects of sulfoxide chemistry. Specifically designed t-butyl and propanenitrile sulfoxides tethered to indole-2-carboxamide were used as a source of intramolecular sulfenylating agents to synthesize novel indolo[3,2-b]-1-5-benzothiazepinones which are structurally analogous to the other biologically active benzothiazepinones. This study reveals that the intramolecular cyclization of sulfoxide follows an electrophilic sulfenylation (Sulfoxide Electrophilic Sulfenylation, SES) reaction pathway. Evidence of the absence of sulfenic acid as a transient reactive intermediate in such intramolecular cyclization is also provided.

In another study, sulfoxide was used as a “protecting group” of thioether to synthesize 8-membered, indole substituted, thiazocine-2-acetic acid derivative …

Controls On The Basal Water Pressure In Subglacial Channels Near The Margin Of The Greenland Ice Sheet, Andreas P. Ahlstrøm, Johan J. Mohr, Niels Reeh, Erik Lintz Christensen, Roger Hooke

Earth Science Faculty Scholarship

Assuming a channelized drainage system in steady state, we investigate the influence of enhanced surface melting on the water pressure in subglacial channels, compared to that of changes in conduit geometry, ice rheology and catchment variations. The analysis is carried out for a specific part of the western Greenland ice-sheet margin between 66 degrees N and 66 degrees 30' N using new high-resolution digital elevation models of the subglacial topography and the ice-sheet surface, based on an airborne ice-penetrating radar survey in 2003 and satellite repeat-track interferometric synthetic aperture radar analysis of European Remote-sensing Satellite 1 and 2 (ERS-1/-2) imagery, …

Increasing Silicon Concentrations In Bohemian Forest Lakes, J. Veselý, V. Majer, J. Kopácek, J. Safanda, Stephen A. Norton

Earth Science Faculty Scholarship

Long-term trends of dissolved silicon (Si) concentrations in five glacial lakes in the Bohemian Forest, Czech Republic, recovering from acidification show higher mobility of Si from the soil to surface waters despite lower atmospheric deposition of acids. Si increased by 0.95 to 1.95 mu mol yr(-1) (36 to 51%) from 1986-2004 and with increasing pH. A change in soil solution conditions because of a sharp decrease in acidic deposition has led to marked decline in Al mobility and to considerable decreases in dissolved Al, especially Al3+. The increase in Si may be related to: (1) unblocking of the inhibitory effect …

Lgm Summer Climate On The Southern Margin Of The Laurentide Ice Sheet: Wet Or Dry?, David H. Bromwich, E. Richard Toracinta, Robert J. Oglesby, James L. Fastook, Terence J. Hughes

Earth Science Faculty Scholarship

Regional climate simulations are conducted using the Polar fifth-generation Pennsylvania State University (PSU)-NCAR Mesoscale Model (MM5) with a 60-km horizontal resolution domain over North America to explore the summer climate of the Last Glacial Maximum (LGM: 21 000 calendar years ago), when much of the continent was covered by the Laurentide Ice Sheet (LIS). Output from a tailored NCAR Community Climate Model version 3 (CCM3) simulation of the LGM climate is used to provide the initial and lateral boundary conditions for Polar MM5. LGM boundary conditions include continental ice sheets, appropriate orbital forcing, reduced CO2 concentration, paleovegetation, modified sea surface …

Stratigraphic Variation Within Polar Firn Caused By Differential Accumulation And Ice Flow: Interpretation Of A 400 Mhz Short-Pulse Radar Profile From West Antarctica, Steven A. Arcone, Vandy Blue Spikes, Gordon S. Hamilton

Earth Science Faculty Scholarship

We investigate causes of the stratigraphic variation revealed in a 177 km, 400 MHz short-pulse radar profile of firn from West Antarctica. The profile covers 56 m depth, and its direction was close to those of the ice flow and mean wind. The average, near-surface accumulation rates calculated from the time delays of one radar horizon consistently show minima on leeward slopes and maxima on windward slopes, confirming an earlier study based on stake observations. The stratigraphic variation includes up to 30 m depth variation in individual horizons over tens of km, fold limbs that become progressively steeper with depth, …

Stable-Isotope Time Series And Precipitation Origin From Firn-Core And Snow Samples, Altai Glaciers, Siberia, Vladimir B. Aizen, Elena M. Aizen, Koji Fujita, Stanislav A. Nikitin, Karl J. Kreutz, L. Nozomu Takeuchi

Earth Science Faculty Scholarship

In the summers of 2001 and 2002, glacio-climatological research was performed at 4110-4120 m a.s.l. on the Belukha snow/firn plateau, Siberian Altai. Hundreds of samples from snow pits and a 21 m snow/firn core were collected to establish the annual/seasonal/monthly depth-accumulation scale, based on stable-isotope records, stratigraphic analyses and meteorological and synoptic data. The fluctuations of water stable-isotope records show well-preserved seasonal variations. The delta(18)O and delta D relationships in precipitation, snow pits and the snow/firn core have the same slope to the covariance as that of the global meteoric water line. The origins of precipitation nourishing the Belukha plateau …

A New Velocity Map For Byrd Glacier, East Antarctica, From Sequential Aster Satellite Imagery, Leigh Stearns, Gordon Hamilton

Earth Science Faculty Scholarship

New ice-velocity measurements are obtained for the main trunk of Byrd Glacier, East Antarctica, using recently acquired Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery. The velocities are derived from the application of a cross-correlation technique to sequential images acquired in 2000 and 2001. Images were co-registered and ortho-rectified with the aid of a digital elevation model (DEM) generated from ASTER stereo imagery. This paper outlines the process of DEM generation, image co-registration and correction, and the application of the cross-correlation technique to obtain ice velocities. Comparison of the new velocity map with earlier measurements of velocity from 1978 …

A 200 Year Sulfate Record From Sixteen Antarctic Ice Cores And Associations With Southern Ocean Sea-Ice Extent, D. Dixon, Paul Andrew Mayewski, S. Kaspari, Karl J. Kreutz, Gordon S. Hamilton, Kirk A. Maasch, Sharon B. Sneed, M. J. Handley

Earth Science Faculty Scholarship

Chemistry data from 16, 50-115 m deep, sub-annually dated ice cores are used to investigate spatial and temporal concentration variability of sea-salt (ss) SO42- and excess (xs) SO42- over West Antarctica and the South Pole for the last 200 years. Low-elevation ice-core sites in western West Antarctica contain higher concentrations Of SO42- as a result of cyclogenesis over the Ross Ice Shelf and proximity to the Ross Sea Polynya. Linear correlation analysis of 15 West Antarctic ice-core SO42- time series demonstrates that at several sites concentrations Of ssSO(4)(2-) are higher when sea-ice (SIE) extent is greater, and the inverse for …

An Ice-Core Proxy For Antarctic Circumpolar Zonal Wind Intensity, Yuping Yan, Paul Andrew Mayewski, Shichang Kang, Eric Meyerson

Earth Science Faculty Scholarship

Using US National Centers for Environmental Prediction/US National Center for Atmospheric Research re-analysis data, we investigate the relationships between crustal ion (nssCa(2+)) concentrations from three West Antarctic ice cores, namely, Siple Dome (SD), ITASE00-1 (IT001) and ITASE01-5 (IT015), and primary components of the climate system, namely, air pressure/geopotential height, zonal (u) and meridional (v) wind strength. Linear correlation analyses between nssCa(2+) concentrations and both air-pressure and wind fields for the period of overlap between records indicate that the SD nssCa(2+) variation is positively correlated with spring circumpolar zonal wind, while IT001 nssCa(2+) has a positive correlation with circumpolar zonal wind …

Multi-Decadal Record Of Ice Dynamics On Daugaard Jensen Gletscher, East Greenland, From Satellite Imagery And Terrestrial Measurements, Leigh A. Stearns, Gordon S. Hamilton, Niels Reeh

Earth Science Faculty Scholarship

The history of ice velocity and calving front position of Daugaard Jensen Gletscher, a large outlet glacier in East Greenland, is reconstructed from field measurements, aerial photography and satellite imagery for the period 1950-2001. The calving terminus of the glacier has remained in approximately the same position over the past similar to 50 years. There is no evidence of a change in ice motion between 1968 and 2001, based on a comparison of velocities derived from terrestrial surveying and feature tracking using sequential satellite images. Estimates of flux near the entrance to the fjord vs snow accumulation in the interior …

Phase Structure Of Radar Stratigraphic Horizons Within Antarctic Firn, Steven A. Arcone, Vandy Blue Spikes, Gordon S. Hamilton

Earth Science Faculty Scholarship

We have recorded reflection profiles of firn through large areas of West Antarctica and part of the East Antarctic plateau using 400 MHz short-pulse radar. The locations show accumulation rates that vary from well above to well below the vertical radar resolution. Most reflection horizons have extensive lateral continuity, and are composed of distinctive wavelets with a consistent phase polarity sequence within their successive half-cycles. We modeled these waveforms, and conclude that they arise from thin, double layers of ice over hoar, which is consistent with the standard model of firn stratification. In addition, we conclude that ice/hoar layers are …

High-Resolution Ice Cores From Us Itase (West Antarctica): Development And Validation Of Chronologies And Determination Of Precision And Accuracy, Eric J. Steig, Paul Andrew Mayewski, Daniel A. Dixon, Susan D. Kaspari, Markus M. Frey, David P. Schneider, Stephen A. Arcone, Gordon S. Hamilton, Vandy Blue Spikes, Mary Albert, Deb Meese, Anthony J. Gow, Christopher A. Shuman, James W.C. White, Sharon Sneed, Joseph Flaherty, Mark Wumkes

Earth Science Faculty Scholarship

Shallow ice cores were obtained from widely distributed sites across the West Antarctic ice sheet, as part of the United States portion of the International Trans-Antarctic Scientific Expedition (US ITASE) program. The US ITASE cores have been dated by annual-layer counting, primarily through the identification of summer peaks in non-sea-salt sulfate (nssSO(4)(2-)) concentration. Absolute dating accuracy of better than 2 years and relative dating accuracy better than 1 year is demonstrated by the identification of multiple volcanic marker horizons in each of the cores, Tambora, Indonesia (1815), being the most prominent. Independent validation is provided by the tracing of isochronal …

Solar Forcing Recorded By Aerosol Concentrations In Coastal Antarctic Glacier Ice, Mcmurdo Dry Valleys, Nancy A.N. Bertler, Paul Andrew Mayewski, Sharon B. Sneed, Tim R. Naish, Uwe Morgenstern, Peter J. Barrett

Earth Science Faculty Scholarship

Ice-core chemistry data from Victoria Lower Glacier, Antarctica, suggest, at least for the last 50 years, a direct influence of solar activity variations on the McMurdo Dry Valleys (MDV) climate system via controls on air-mass input from two competing environments: the East Antarctic ice sheet and the Ross Sea. During periods of increased solar activity, when total solar irradiance is relatively high, the MDV climate system appears to be dominated by air masses originating from the Ross Sea, leading to higher aerosol deposition. During reduced solar activity, the Antarctic interior seems to be the dominant air-mass source, leading to lower …

Spatial Patterns In Mass Balance Of The Siple Coast And Amundsen Sea Sectors, West Antarctica, Gordon S. Hamilton, V. Blue Spikes, Leigh A. Stearns

Earth Science Faculty Scholarship

Local rates of change in ice-sheet thickness were calculated at IS sites in West Antarctica using the submergence velocity technique. This method entails a comparison of the vertical velocity of the ice sheet, measured using repeat global positioning system surveys of markers, and local long-term rates of snow accumulation obtained using firn-core stratigraphy. Any significant difference between these two quantities represents a thickness change with time. Measurements were conducted at sites located similar to 100-200 km apart along US ITASE traverse routes, and at several isolated locations. All but one of the sites are distributed in the Siple Coast and …

Solar Forcing Of The Polar Atmosphere, Paul Andrew Mayewski, Kirk A. Maasch, Yuping Yan, Shichang Kang, Eric A. Meyerson, Sharon B. Sneed, Susan D. Kaspari, Daniel A. Dixon, Erich C. Osterberg, Vin I. Morgan, Tas Van Ommen, Mark A.J. Curran

Earth Science Faculty Scholarship

We present highly resolved, annually dated, calibrated proxies for atmospheric circulation from several Antarctic ice cores (ITASE (International Trans-Antarctic Scientific Expedition), Siple Dome, Law Dome) that reveal decadal-scale associations with a South Pole ice-core Be-10 proxy for solar variability over the last 600 years and annual-scale associations with solar variability since AD 1720. We show that increased (decreased) solar irradiance is associated with increased (decreased) zonal wind strength near the edge of the Antarctic polar vortex. The association is particularly strong in the Indian and Pacific Oceans and as such may contribute to understanding climate forcing that controls drought in …

The International Trans-Antarctic Scientific Expedition (Itase): An Overview, Paul Andrew Mayewski, Massimo Frezzotti, Nancy A.N. Bertler, Tas Van Ommen, Gordon S. Hamilton, Tim H. Jacka, Brian Welch, Markus Frey, Dahe Qin, Jiawen Ren, Jefferson Simöes, Michel Fily, Hans Oerter, Fumihiko Nishio, Elisabeth Isaksson, Robert Mulvaney, Per Holmund, Volodya Lipenkov, Ian Goodwin

Earth Science Faculty Scholarship

From its original formulation in 1990 the International Trans-Antarctic Scientific Expedition (ITASE) has had as its primary aim the collection and interpretation of a continent-wide array of environmental parameters assembled through the coordinated efforts of scientists from several nations. ITASE offers the ground-based opportunities of traditional-style traverse travel coupled with the modern technology of CPS, crevasse detecting radar, satellite communications and multidisciplinary research. By operating predominantly in the mode of an oversnow traverse, ITASE offers scientists the opportunity to experience the dynamic range of the Antarctic environment. ITASE also offers an important interactive venue for research similar to that afforded …

Snow Chemistry Across Antarctica, Nancy Bertler, Paul Andrew Mayewski, Alberto Aristarain, P. Barrett, S. Becagli, Ronaldo Torma Bernardo, Xiao Cunde, M. Curran, Qin Dahe, Daniel Dixon, Francisco Adolfo Ferron, H. Fischer, Markus Frey, M. Frezzotti, F. Fundel, Christophe Genthon, R. Gragani, Gordon Hamilton, M. Handley, Sungmin Hong, E. Isaksson, Ren Jiawen, Kokichi Kamiyama, Satoru Kanamori, Eija Karkas, L. Karlöf, S. Kaspari, K. Kreutz, A. Kurbatov, E. Meyerson, Hideaki Motoyama, R. Mulvaney, Zhang Mingjun, H. Oerter, E. Osterberg, M. Proposito, A. Pyne, U. Ruth, Jefferson Cardia Simoes, B. Smith, S. Sneed, Kimmo Teinila, F. Traufetter, R. Udisti, Aki Virkkula, Okitsugu Watanabe, B. Williamson, E. Wolff, Li Zhongqin

Earth Science Faculty Scholarship

An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO₃, SO₄) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve …

The International Trans-Arctic Scientific Expedition (Itase): An Overview, Paul Andrew Mayewski, Massimo Frezzotti, Nancy Bertler, Tas Van Ommen, Gordon S. Hamilton, Tim H. Jacka, Brian Welch, Markus Frey, Dahe Qin, Jiawen Ren, Jefferson Simões, Michel Fily, Hans Oerter, Fumihiko Nishio, Elisabeth Isaksson, Robert Mulvaney, Per Holmund, Volodya Lipenkov, Ian Goodwin

Earth Science Faculty Scholarship

From its original formulation in 1990 the International Trans-Antarctic Scientific Expedition (ITASE) has had as its primary aim the collection and interpretation of a continent-wide array of environmental parameters assembled through the coordinated efforts of scientists from several nations. ITASE offers the ground-based opportunities of traditional-style traverse travel coupled with the modern technology of GPS, crevasse detecting radar, satellite communications and multidisciplinary research. By operating predominantly in the mode of an oversnow traverse, ITASE offers scientists the opportunity to experience the dynamic range of the Antarctic environment. ITASE also offers an important interactive venue for research similar to that afforded …

Sustainable Tourism Along Maine's Coast, Natalie Springuel

Maine Sea Grant Publications

Tourism is Maine's largest industry. In 2003, tourism generated $ 13.4 billion in sales of goods and services. In 2004, tourism provided for 176,633 jobs, generated $3.8 billion in wages, and $530 million in tax revenues. Governor John Baldacci formally recognized the economic and ecological importance of tourism by highlighting it as one of the five primary industries at the Governor's 2003 Conference on Natural Resource-based Industries. Access to the natural resource base, and the need to collaborate with other resource-dependent industries, were identified at the conference as cutting across multiple industries, including tourism. Since the Governor's Conference, several studies …

Tracking Beach Erosion Could Help Management, Maine Sea Grant

Maine Sea Grant Publications

Although sandy beaches represent only about one percent of Maine's 3500-mile coastline, they are vitally important to the state's economy as recreational resources, provide crucial wildlife habitat, and buffer the coast against storms. However, many of Maine's beaches are threatened, mainly by erosion from coastal engineering and natural forces. Engineering structures-such as jetties and seawalls-built to create navigable harbors and protect, beachfront property, may impact the recreational beach. They can interfere with the natural distribution of sand and cause beaches to erode more rapidly or sand to accumulate in unwanted places. Some towns try, often without success, to fix their …