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1998

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Articles 1741 - 1770 of 2574

Full-Text Articles in Physical Sciences and Mathematics

Lave Caves Of Kilimanjaro. Mawenzi Lava Tubes, Clive Ward Jan 1998

Lave Caves Of Kilimanjaro. Mawenzi Lava Tubes, Clive Ward

International Journal of Speleology

This is the first short report on the exploration of lava tubes in the upper part of Kilimanjaro. The area seems to be extremely interesting from vulcanospeleological point of view.


Lava Caves Of Grande Comore, Indian Ocean: An Initial Reconnaissance, September 1997, Gregory J. Middleton Jan 1998

Lava Caves Of Grande Comore, Indian Ocean: An Initial Reconnaissance, September 1997, Gregory J. Middleton

International Journal of Speleology

What are believed to have been the first speleological investigations in the Comoros Islands were carried out on Grande Comore island between 7 and 13 September 1997. A number of caves were located with the help of local informants and the more significant ones surveyed. Exploration of some caves was not able to be completed. The potential for further significant discoveries is believed to be high.


"Pit Craters", Lava Tubes, And Open Vertical Volcanic Conduits In Hawaii: A Problem In Terminology, William R. Halliday Jan 1998

"Pit Craters", Lava Tubes, And Open Vertical Volcanic Conduits In Hawaii: A Problem In Terminology, William R. Halliday

International Journal of Speleology

Almost from the 1849 publication of the term pit crater, volcanologists have disagreed about the parameters differentiating these features from other vertical volcanic structures. Kaluaiki is a jameo giving entry to Thurston Lava Tube in Hawaii Volcanoes National Park. Long-standing misidentification of it as a pit crater is an example of misunderstandings arising from the lack of a clear definition of pit crater. In general, pit craters are unrelated to lava tube caves genetically, but two special cases are discussed. One probably is genetically related to a rift tube deep below the surface; the other is a complex of a …


Lava Tube Remelt By Radiant Heat And Burning Gasses, Kevin Allred Jan 1998

Lava Tube Remelt By Radiant Heat And Burning Gasses, Kevin Allred

International Journal of Speleology

Some volcanologists assume that interior surfaces of hot lava tubes can commonly be remelted by burning gases and radiant heat. Pending further data, this appears to be unlikely.


Xps Investigations On Conducting Polymers, Ş. Süzer, Ö. Bi̇rer, U.A. Sevi̇l, O. Güven Jan 1998

Xps Investigations On Conducting Polymers, Ş. Süzer, Ö. Bi̇rer, U.A. Sevi̇l, O. Güven

Turkish Journal of Chemistry

X-ray photoelectron spectroscopy, XPS, was used for the characterization of electrically conducting polymeric materials. In the spectrum of polypyrrole, PPy, the Nls region exhibits two peaks, at 402.0 and 399.8 eV, corresponding to -N$^+$- and -N- moieties, respectively. The intensity of the N$^+$ peak decreases as the material loses its conductivity, hence the ratio of the experimentally derived N$^+$/C atomic ratio correlates exponentially with the measured conductivity. A similar observation also exists between the F$^-$/C atomic ratio both in polypyrrole and polythiophene. In the XPS spectrum of the composite material prepared using polyaniline, PAN and polyvinylchloride, PVC, two different kinds …


Positive Solutions For A Concave Semipositone Dirichlet Problem, Alfonso Castro, Ratnasingham Shivaji Jan 1998

Positive Solutions For A Concave Semipositone Dirichlet Problem, Alfonso Castro, Ratnasingham Shivaji

All HMC Faculty Publications and Research

No abstract provided for this article


Average-Case Lower Bounds For Noisy Boolean Decision Trees, William Evans, Nicholas Pippenger Jan 1998

Average-Case Lower Bounds For Noisy Boolean Decision Trees, William Evans, Nicholas Pippenger

All HMC Faculty Publications and Research

We present a new method for deriving lower bounds to the expected number of queries made by noisy decision trees computing Boolean functions. The new method has the feature that expectations are taken with respect to a uniformly distributed random input, as well as with respect to the random noise, thus yielding stronger lower bounds. It also applies to many more functions than do previous results. The method yields a simple proof of the result (previously established by Reischuk and Schmeltz) that almost all Boolean functions of n arguments require $\Me(n \log n)$ queries, and strengthens this bound from the …


A Minmax Principle, Index Of The Critical Point, And Existence Of Sign Changing Solutions To Elliptic Boundary Value Problems, Alfonso Castro, Jorge Cossio, John M. Neuberger Jan 1998

A Minmax Principle, Index Of The Critical Point, And Existence Of Sign Changing Solutions To Elliptic Boundary Value Problems, Alfonso Castro, Jorge Cossio, John M. Neuberger

All HMC Faculty Publications and Research

In this article we apply the minmax principle we developed in [6] to obtain sign-changing solutions for superlinear and asymptotically linear Dirichlet problems.

We prove that, when isolated, the local degree of any solution given by this minmax principle is +1. By combining the results of [6] with the degree-theoretic results of Castro and Cossio in [5], in the case where the nonlinearity is asymptotically linear, we provide sufficient conditions for:

i) the existence of at least four solutions (one of which changes sign exactly once),

ii) the existence of at least five solutions (two of which change sign), and …


Convergence Of Random Walks On The Circle Generated By An Irrational Rotation, Francis E. Su Jan 1998

Convergence Of Random Walks On The Circle Generated By An Irrational Rotation, Francis E. Su

All HMC Faculty Publications and Research

Fix . Consider the random walk on the circle which proceeds by repeatedly rotating points forward or backward, with probability , by an angle . This paper analyzes the rate of convergence of this walk to the uniform distribution under ``discrepancy'' distance. The rate depends on the continued fraction properties of the number . We obtain bounds for rates when is any irrational, and a sharp rate when is a quadratic irrational. In that case the discrepancy falls as (up to constant factors), where is the number of steps in the walk. This is the first example of a sharp …


Salinity Action Plan : Wetland Vegetation Monitoring, 1997/1998, G. Ogden, R. H. Froend Jan 1998

Salinity Action Plan : Wetland Vegetation Monitoring, 1997/1998, G. Ogden, R. H. Froend

Research outputs pre 2011

This report represents the vegetation component of a project designed to provide on-going monitoring of wetland salinity and biological resources in wetlands of the agricultural zone of south-west Western Australia. Maintenance of wetland biological diversity in the agricultural zone is one of the major objectives of the Salinity Action Plan. Due to their low position in the landscape, wetlands are the habitat most affected by salinisation...


Newton's Cubic Roots, Lisette G. De Pillis Jan 1998

Newton's Cubic Roots, Lisette G. De Pillis

All HMC Faculty Publications and Research

No abstract included in this article


Kentucky River Basin Water Quality Assessment Study, L. Ormsbee, L. Jarrett, B. Perkins Jan 1998

Kentucky River Basin Water Quality Assessment Study, L. Ormsbee, L. Jarrett, B. Perkins

KWRRI Research Reports

The current report summarizes the work associated with the construction, calibration, and application of the CE-QUAL-W2 water quality model to the Kentucky River. In applying the model to the Kentucky River System, the primary objective was to assess the impact of the operation of low-level control valves on water quality of the Kentucky River. This was accomplished by modeling the impact of the valves for low flow conditions associated with the 1930 drought of record along with projections for the year 2020. The results of this study indicate that for the modeled scenario, the proposed valves can be used to …


Development Of A Kentucky Cso Database, L. Ormsbee Jan 1998

Development Of A Kentucky Cso Database, L. Ormsbee

KWRRI Research Reports

This report provides an overview of several products developed for the management of CSO data for the state of Kentucky. These products have been developed in fulfillment of the Memorandum of Agreement No. 13814 between the University of Kentucky and the Environmental Protection Cabinet. The developed products include: 1) an overall management structure, 2) a stand-alone data management computer program, 3) background maps for each CSO city, 4) a customized Access database management environment, 5) a computer program for automating monthly CSO discharge monitoring reports, and 6) a customized Arcview 3 project for visualization and management of physical CSO datasets.


A Teacher's Guide And Study Kit On The Santa Rosa Plateau Ecological Reserve For Middle School Students, Katharine Marie Havert Jan 1998

A Teacher's Guide And Study Kit On The Santa Rosa Plateau Ecological Reserve For Middle School Students, Katharine Marie Havert

Theses Digitization Project

No abstract provided.


Cyclic Cutwidth Of Three Dimensional Cubes, Ray N. Gregory Jan 1998

Cyclic Cutwidth Of Three Dimensional Cubes, Ray N. Gregory

Theses Digitization Project

No abstract provided.


A Study Of Optimization In Hilbert Space, John Awunganyi Jan 1998

A Study Of Optimization In Hilbert Space, John Awunganyi

Theses Digitization Project

No abstract provided.


State Sum Invariants Of Three Manifolds, Sharon Angela Newman-Gomez Jan 1998

State Sum Invariants Of Three Manifolds, Sharon Angela Newman-Gomez

Theses Digitization Project

No abstract provided.


Torus Embedding And Its Applications, Rick Hung Nguyenhuu Jan 1998

Torus Embedding And Its Applications, Rick Hung Nguyenhuu

Theses Digitization Project

No abstract provided.


Hydrogeology In The Vicinity Of The Nebraska Management Systems Evaluation Area Site, Centra! Nebraska, Virginia L. Mcguire, John M. Kilpatrick Jan 1998

Hydrogeology In The Vicinity Of The Nebraska Management Systems Evaluation Area Site, Centra! Nebraska, Virginia L. Mcguire, John M. Kilpatrick

United States Geological Survey: Publications

From 1991 to 1992, the U.S. Geological Survey participated with the U.S. Department of Agriculture and the University of Nebraska-Lincoln in research activities at the Nebraska Management Systems Evaluation Area (MSEA) site near Shelton, Nebraska. The purpose of the U.S. Geological Survey study was to define the hydrogeologic system in the vicinity of the Nebraska MSEA site to aid the interpretation of ground-water sampling results by other researchers. The primary aquifer in the study area is the High Plains aquifer, which consists of an unconfined part, the shallow aquifer; a silt and clay unit that acts as a confining layer; …


Water Quality In The Central Nebraska Basins, Nebraska, 1992-95, S. A. Frenzel, R. B. Swanson, T. L. Huntzinger, J. K. Stamer, P. J. Emmons, Ronald B. Zelt Jan 1998

Water Quality In The Central Nebraska Basins, Nebraska, 1992-95, S. A. Frenzel, R. B. Swanson, T. L. Huntzinger, J. K. Stamer, P. J. Emmons, Ronald B. Zelt

United States Geological Survey: Publications

This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Central Nebraska Basins Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in waterresource management. Indeed, this report addresses many of the concerns raised by regulators, water-utility managers, industry representatives, and other scientists, engineers, public officials, and members of stakeholder groups who provided advice and input to the USGS during this NAWQA Study-Unit investigation. Yet, the information contained here may also interest those who …


Stable Isotope Analyses Of Tooth Annuli Reveal Temporal Dietary Records: An Example Using Stellar Sea Lions, Keith Hobson, John Sease Jan 1998

Stable Isotope Analyses Of Tooth Annuli Reveal Temporal Dietary Records: An Example Using Stellar Sea Lions, Keith Hobson, John Sease

United States Department of Commerce: Staff Publications

Stable isotope analysis of teeth of marine mammals can provide valuable information on trophic level and source of feeding. However, the isotopic analysis of whole teeth presents only an average dietary estimate for individuals across the period of growth of that tooth. While such analyses can be valuable, particularly in the case of fossil material, in contrast, isotopic analysis of individual annuli of teeth can provide dietary information for each year of tooth growth, in some cases representing the whole of the animal's life. We measured stable-carbon isotope ratios (13C/12C) in the inorganic (hydroxyapatire) and stable-nitrogen …


Development Of Seed Treatments To Control Blackbirds, Michael L. Avery, David Decker, John S. Humphrey Jan 1998

Development Of Seed Treatments To Control Blackbirds, Michael L. Avery, David Decker, John S. Humphrey

Vertebrate Pest Conference Proceedings: 18th (1998)

Bird repellents to protect seeds are a potentially important aspect of integrated vertebrate pest management strategies. Yet, there currently are no repellents registered for seed treatment uses. This is due not to lack of effective candidate compounds, but to monetary and regulatory constraints that inhibit commercialization of promising compounds. Two examples of this dilemma are methiocarb and anthraquinone, each of which has considerable potential for bird repellent uses and each of which faces considerable registration hurdles as prospective seed treatment compounds. A concerted, coordinated effort among private industry, producer groups, and state and federal agencies may be the best strategy …


Evaluation Of Electronic Frightening Devices As White-Tailed Deer Deterrents, Jerrold L. Belant, Thomas W. Seamans, Laura A. Tyson Jan 1998

Evaluation Of Electronic Frightening Devices As White-Tailed Deer Deterrents, Jerrold L. Belant, Thomas W. Seamans, Laura A. Tyson

Vertebrate Pest Conference Proceedings: 18th (1998)

The authors evaluated the effectiveness of the motion-activated Usonic Sentry (with and without strobe), motion-activated Yard Gard, and Electronic Guard for deterring white-tailed deer (Odocoileus virginianus) from preferred feeding areas from February to April 1996. Two four-week experiments were conducted, monitoring deer use (number of intrusions and corn consumption) at eight feeding stations in a 2,200 ha fenced facility in northern Ohio with high deer densities (≥ 38/km2). During these experiments, one of the devices was positioned at each of four sites. The mean (± SE, n = 4) daily number of deer intrusions at feeding …


Predator Urines As Chemical Barriers To White-Tailed Deer, Jerrold L. Belant, Thomas W. Seamans, Laura A. Tyson Jan 1998

Predator Urines As Chemical Barriers To White-Tailed Deer, Jerrold L. Belant, Thomas W. Seamans, Laura A. Tyson

Vertebrate Pest Conference Proceedings: 18th (1998)

The authors assessed whether bobcat (Lynx rufus) or coyote (Canis latrans) urine could reduce white-tailed deer (Odocoileus virginianus) use of established feeding areas or trails. A four-week experiment evaluating deer use of eight feeding stations, four each with coyote or bobcat urine was conducted at a 2,200 ha fenced facility in northern Ohio with high deer densities (38/km2). At this same facility, the authors also monitored deer use of four trails where coyote urine was applied. For both experiments, urine was placed in holders positioned at ground level within 2 m of …


The Development Of An Integrated Pest Management Plan For Roof Rats In Hawaiian Macadamia Orchards, Earl W. Campbell Iii, Ann E. Koehler, Robert T. Sugihara Jan 1998

The Development Of An Integrated Pest Management Plan For Roof Rats In Hawaiian Macadamia Orchards, Earl W. Campbell Iii, Ann E. Koehler, Robert T. Sugihara

Vertebrate Pest Conference Proceedings: 18th (1998)

Roof rats (Rattus rattus) damage an estimated 5 to 10% of the developing nut crop in Hawaiian macadamia (Macadamia integrifolia) orchards. Relevant aspects of roof rat biology in macadamia orchards have and continue to be studied with the ultimate goal of developing an ecologically sound and cost-effective integrated pest management plan. The field component of a two-year study of roof rat populations in macadamia orchards has recently been completed. The goal of this study is to clarify the relationship between roof rat seasonal abundance, macadamia flowering, and nut production on five orchards in three regions on …


Review Of Bird Repellents, Larry Clark Jan 1998

Review Of Bird Repellents, Larry Clark

Vertebrate Pest Conference Proceedings: 18th (1998)

Despite a general perception that there is an abundance of nonlethal control technologies, the fact remains that there are fewer registered products and active ingredients for repellents in the U.S. than there were 10 and 20 years ago. This review discusses the technical issues relating to the discovery, formulation, and delivery of chemical repellents, and suggests future avenues of research that would improve our ability to develop effective chemical repellents.


Potential Bird Repellents To Reduce Bird Damage To Lettuce Seed And Seedlings, John L. Cummings, Patricia A. Pochop, Christi A. Yoder, James E. Davis Jr. Jan 1998

Potential Bird Repellents To Reduce Bird Damage To Lettuce Seed And Seedlings, John L. Cummings, Patricia A. Pochop, Christi A. Yoder, James E. Davis Jr.

Vertebrate Pest Conference Proceedings: 18th (1998)

The authors evaluated the effectiveness of ReJeX-iT® AG-145, Mesurol®, activated charcoal, lime, and fipronil to reduce homed lark damage to lettuce seeds and seedlings. In Experiment 1, homed larks consumed significantly more feed mixture (50:50 grains and lettuce seed) than untreated clay-coated lettuce seed in a three-day choice-test. In Experiment 2, where clay-coated lettuce seed was treated with ReJeX-iT® AG- 145, Mesurol®, activated charcoal, or lime, there was no significant difference in consumption of untreated clay-coated lettuce seed and treated clay-coated lettuce seed. Homed larks consumed insignificant amounts of all seed treatments including untreated coated lettuce seed. In this experiment …


Fertility Control In Coyotes: Is It A Potential Management Tool?, Thomas J. De Liberto, Eric M. Gese, Frederick F. Knowlton, J. Russell Mason, Michael R. Conover, Lowell Miller, Robert H. Schmidt, Michael K. Holland Jan 1998

Fertility Control In Coyotes: Is It A Potential Management Tool?, Thomas J. De Liberto, Eric M. Gese, Frederick F. Knowlton, J. Russell Mason, Michael R. Conover, Lowell Miller, Robert H. Schmidt, Michael K. Holland

Vertebrate Pest Conference Proceedings: 18th (1998)

Fertility control in wildlife is emerging as a potential management tool. Published research on feral horses, deer, rodents, and rabbits suggest an effective agent producing reversible infertility in these species could be developed. Furthermore, anecdotal reports suggest that infertility can be induced in a greater array of species. In this paper, the authors review methods of fertility control being studied for application in wildlife and focus on their studies designed to evaluate the effectiveness of fertility control agents in coyotes (Canis latrans). Immunocontraception using porcine zona pellucida (PZP) is currently the most promising method of fertility control in …


Population Dynamics: The Foundation Of Wildlife Damage Management For The 21st Century, Richard A. Dolbeer Jan 1998

Population Dynamics: The Foundation Of Wildlife Damage Management For The 21st Century, Richard A. Dolbeer

Vertebrate Pest Conference Proceedings: 18th (1998)

To justify and defend lethal or reproductive control programs to solve vertebrate pest problems, wildlife biologists must have a sound understanding of the population status and dynamics of the problem species. Models are essential to project how populations will respond to proposed management actions, providing a scientific foundation to counter the emotional debates that often arise. Four population models (PM1 to PM4) for predicting population responses are described. PM1 and PM2 explore the relative efficacy of reproductive and lethal control for vertebrate species over 10-year intervals. PM3 simulates population responses to actual management actions through 10-year intervals. PM4 simulates population …


Wildlife Information Sources And Search Methods On The Internet, Diana L. Dwyer Jan 1998

Wildlife Information Sources And Search Methods On The Internet, Diana L. Dwyer

Vertebrate Pest Conference Proceedings: 18th (1998)

Vertebrate pest damage information is pulled from a variety of disciplines ranging from wildlife management to psychology. The Internet has opened the door to what seems to be an unending number of information sources. Researchers can become overwhelmed by the choices and different levels of information available. The correct use of search engines and a checklist of criteria to evaluate the quality of information obtained can help to eliminate the extraneous information and make the time spent on the Internet more productive. There are a large number of wildlife, biology, environmental, and other related sites that are especially useful to …