Physical Sciences and Mathematics Commons^™

Kentucky's Coal Industry: Historical Trends And Future Opportunities, Gerald A. Weisenfluh, James C. Cobb, John C. Ferm, Carol L. Ruthven

Information Circular--KGS

Coal has been produced in Kentucky since the late 18th century. In the early years, all mining was by underground methods, but surface mining became the dominant method during and after World War II. In recent years, surface-mine production in both fields has decreased while underground mining has increased.

In the last half of this century, the traditional steam coal market for locomotives has virtually disappeared, leaving electric power generation and coking coal for the steel industry as the principal markets. More than half of all coal produced in the State has been produced in the last 25 years. Whether …

Effect Of Parameter Distributions On Uncertainty Analysis Of Hydrologic Models, C. Thomas Haan, Daniel E. Storm, T. Al-Issa, Sandeep Prabhu, George J. Sabbagh, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Increasing concern about the accuracy of hydrologic and water quality models has prompted interest in procedures for evaluating the uncertainty associated with these models. If a Monte Carlo simulation is used in an uncertainty analysis, assumptions must be made relative to the probability distributions to assign to the model input parameters. Some have indicated that since these parameters can not be readily determined, uncertainty analysis is of limited value. In this article we have evaluated the impact of parameter distribution assumptions on estimates of model output uncertainty. We conclude that good estimates of the means and variances of the input …

Validating A Vegetative Filter Strip Performance Model, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards, James A. Ferguson

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) reduce losses of nutrients, solids, and other materials from land area treated with fertilizers and manures. A number of models are available that simulate nutrient and sediment transport in VFS. While VFS effectiveness is considered to depend on lengths of pollutant source area and VFS areas, few published studies have tried to validate these models using variable pollutant source area and VFS area. The objective of this study was to validate an event-based nutrient transport model (Chaubey et al., 1995) that simulates soluble nutrient transport in VFS. This model links three sub-models: modified Green-Ampt infiltration, non-linear …

Impact Of Topographic And Data Resolution On Hydrologic And Nonpoint-Source Pollution Modeling In A Karst Terrane, Alex W. Fogle

Report of Investigations--KGS

To prevent or reduce the contamination of ground water from agricultural sources, Best Management Practices (BMP’s) such as land-use changes, modifications to control surface runoff, various tillage methods, variations in rates and kinds of chemical applications, and handling procedures for chemicals are being employed and analyzed for effectiveness. The effectiveness of a BMP is often estimated before implementation by evaluating the BMP through the use of computer simulation models. The interactions between surface water and ground water that are unique to karst terranes are not incorporated into the frequently used predictive models. The purpose of this study was to document …

Error Estimation Of The Padé Approximation Of Transfer Functions Via The Lanczos Process, Zhaojun Bai, Qiang Ye

Mathematics Faculty Publications

Krylov subspace based moment matching algorithms, such as PVL (Padé approximation Via the Lanczos process), have emerged as popular tools for efficient analyses of the impulse response in a large linear circuit. In this work, a new derivation of the PVL algorithm is presented from the matrix point of view. This approach simplifies the mathematical theory and derivation of the algorithm. Moreover, an explicit formulation of the approximation error of the PVL algorithm is given. With this error expression, one may implement the PVL algorithm that adaptively determines the number of Lanczos steps required to satisfy a prescribed error tolerance. …

Single Magnetic Domains In Magnetotactic Bacteria, Richard B. Frankel, Jin-Ping Zhang, Dennis A. Bazylinski

Physics

Magnetotactic bacteria construct an internal, permanent magnetic dipole based on single magnetic domain particles of magnetite or greigite. The organisms exert a high degree of control over the size and morphology of the particles. This may be relevant in distinguishing biogenic from nonbiogenic iron mineral particles.

Review Of The Future Of U.S. Nuclear Weapons Policy, David W. Hafemeister

Physics

No abstract provided.

Biomineralization Of Magnetic Iron Minerals In Bacteria, Richard B. Frankel, Dennis A. Bazylinski, Dirk Schϋler

Physics

Magnetotactic bacteria orient and migrate along magnetic field lines. This ability is based on a submicron assembly of single-magnetic domain iron mineral particles that elegantly solves the problem of how to construct a magnetic dipole that is large enough to be oriented in the geomagnetic field at ambient temperature, yet fit inside a micron-sized cell. The solution is based on the ability of the bacteria to accumulate high concentrations of iron, and control the deposition, size and orientation of a specific iron mineral at specific locations in the cell.

Heat And Salt Changes On The Continental Shelf West Of The Antarctic Peninsula Between January 1993 And January 1994, John M. Klinck

CCPO Publications

Hydrographic measurements from four cruises between January 1993 and January 1994 over the continental shelf west of the Antarctic Peninsula allow analysis of seasonal changes in heat and salt content of this region. Changes above the permanent pycnocline (about 150 m) follow a seasonal pattern of cooling and increasing in salt from summer to winter and warming and freshening from winter to summer. These near-surface changes expressed as net heating or salting rate, were above 80 W m(-2) and 4 mg salt m(-2) s(-1). The year to year difference was small compared to the seasonal changes. There was no seasonal …

Understanding The Success And Failure Of Oyster Populations: The Importance Of Sampled Variables And Sample Timing, Thomas M. Soniat, Eric N. Powell, Eileen E. Hofmann, John M. Klinck

CCPO Publications

One of the primary obstacles to understanding why some oyster populations are successful and others are not is the complex interaction of environmental variables with oyster physiology and with such population variables as the rates of recruitment and juvenile mortality. A numerical model is useful in investigating how population structure originates out of this complexity. We have monitored a suite of environmental conditions over an environmental gradient to document the importance of short time-scale variations in such variables as food supply, turbidity, and salinity. Then, using a coupled oyster disease population dynamics model, we examine the need for short rime-scale …

Sigma Coordinate Pressure Gradient Errors And The Seamount Problem, George L. Mellor, Lie-Yauw Oey, Tal Ezer

CCPO Publications

In a recent paper by Mellor et al., it was found that, in two-dimensional (x, z) applications with finite horizontal viscosity and zero diffusivity, the velocity error, associated with the evaluation of horizontal density or pressure gradients on a sigma coordinate grid, prognostically disappeared, leaving behind a small and physically insignificant distortion in the density field. The initial error is numerically consistent in that it decreases as the square of the grid increment size. In this paper, we label this error as a sigma error of the first kind. In three-dimensional applications, the authors have encountered an error that did …

Circulation, Vol. 5, No. 2, Center For Coastal Physical Oceanography, Old Dominion University

CCPO Circulation

Winter 1998 issue of CCPO Circulation featuring article "Coastal Oceanographic Research Experiences in Chile"

Suppression Of Switchable Polarization In Kdp By Ionizing Radiation, Timothy D. Usher

Physics Faculty Publications

Switching curves were obtained from KH₂PO₄ single crystals exposed to x-ray radiation for various time intervals, up to 8 h. The applied electric field was varied between 370 and 740 V/cm, as well. The temperature was held constant at 99 K. The switching curves were fit to a three-parameter nucleation and growth model based on the original works by Johnson and Mehl, and independently by Avrami. The two dynamic parameters, characteristic time t_c, and effective domain wall dimensionality n, produced values consistent with unirradiated studies, however, they did not show any clear dependancy on …

Identification Of Past Climate Variability Of The Eastern Pacific Ocean Using Both D13c And D18o Records In Corals From Clipperton Atoll (1994-1906), Lei Ren

Geology Theses and Dissertations

The ENSO (El Nino and the Southern Oscillation) is a fundamental ocean-atmosphere phenomenon that dominates interannual global climate variability. Reconstructing past ENSO events is therefore important for documenting and understanding the past behavior of the global climate system and enabling us to predict future climate change. However, the present understanding of ENSO events has been mainly based on the instrumental record of Pacific climate which provides detailed data only for the past few decades. Recent studies have shown that the stable isotope record in coral skeletons can be used as a valuable indicator of paleoclimatic changes in tropical regions, and …

Stratigraphic And Tectonic Features Of Miocene Basin South Of İmranli And Hafi̇k (Si̇vas), Yavuz Çubuk, Selim İnan

Bulletin of the Mineral Research and Exploration

No abstract provided.

Quaternary Freshwater Fauna Of The Kilbasan Area, Northern Karaman, Ümit Şafak, Güler Taner

Bulletin of the Mineral Research and Exploration

No abstract provided.

Facies Characteristics And Geographic Distribution Of Rhodoliths And Maerls (Red Algae) In Southern Shelf Of The Sea Of Marmara, Nevbahar Atabey

Bulletin of the Mineral Research and Exploration

No abstract provided.

An Approach To The Origin Of Kesi̇kköprü (Bala-Ankara) Iron Deposit, Bilgin Doğan, Taner Ünlü, İ. Sönmez Sayili

Bulletin of the Mineral Research and Exploration

No abstract provided.

An Example For A Pre-Early Ordovician Arc Magmatism From North Turkey: Geochemical Study Of The Çaşurtepe Formation (Bolu, W Pontides), P. Ayda Ustaömer, Erdinç Ki̇pman

Bulletin of the Mineral Research and Exploration

No abstract provided.

Revision On The Species Of Pseudolacazina Caus 1979 (Foraminiferida) From The Different Localities Of Turkey, Ercüment Si̇rel

Bulletin of the Mineral Research and Exploration

No abstract provided.

Sedimentology Of Caliche (Calcrete) Occurrences Of The Kirşehi̇r Region, Eşref Atabey, Nevbahar Atabey, Haydar Kara

Bulletin of the Mineral Research and Exploration

No abstract provided.

Geologic And Mineralogic Investion Of The Northern Konya Lacustrine Units, Zehra Karakaş, Selahattin Kadi̇r

Bulletin of the Mineral Research and Exploration

No abstract provided.

Volcano-Stratigraphy Of Collision-Related Volcanics On The Erzurum-Kars Plateau And Evolution Of Volcanism In The Light Of New K/Ar Age Determinations, Ne Anatolia Turkey, Mehmet Keski̇n

Bulletin of the Mineral Research and Exploration

No abstract provided.

The Geology Of The South Of Manyas (Balikesi̇r) And Tectonic Significance Of Blueschists, H. Serdar Akyüz, Aral I. Okay

Bulletin of the Mineral Research and Exploration

No abstract provided.

Geology Of The Güzelsu Corridor And Its Northern Part In The Central Taurides, Mustafa Şenel, Halil Dalkiliç, İbrahim Gedi̇k, Mualla Serdaroğlu, Sait Meti̇n, Kadri Esentürk, A. Sait Bölükbaşi, Necdet Özgül

Bulletin of the Mineral Research and Exploration

No abstract provided.

Early Devonian Conodonts From Limestone Olistoliths Within The Karasenir Formation Of The Karakaya Complex, Şenol Çapkinoğlu, Osman Bektaş

Bulletin of the Mineral Research and Exploration

No abstract provided.

Benthic Foraminifera (Holocene) Paleobiofacies Of Bosphorus (Golden Horn - Sarayburnu - Üsküdar): A New Approach To Mediterranean-Black Sea Waterway, Mehmet Sakinç

Bulletin of the Mineral Research and Exploration

No abstract provided.

Features Of The Tertiary Volcanism Around Sea Of Marmara, Tuncay Ercan, Ahmet Türkecan, Herve Guillou, Muharrem Satir, Dilek Sevi̇n, Fuat Şaroğlu

Bulletin of the Mineral Research and Exploration

No abstract provided.

Detection Of Potential Aquifer Using Remote Sensing Data And Digital Elevation Model, Sadrazamköy, The Turkish Republic Of Northern Cyprus, Kenan Tüfekçi̇

Bulletin of the Mineral Research and Exploration

No abstract provided.

Neogene-Quaternary Evolution Of The Eastern Marmara Region, Northwest Turkey, Ömer Emre, Tevfik Erkal, Andrey Tchepalyga, Nizamettin Kazanci, Mustafa Keçer, Engin Ünay

Bulletin of the Mineral Research and Exploration

No abstract provided.