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1999

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Articles 2101 - 2130 of 2348

Full-Text Articles in Physical Sciences and Mathematics

Experimental Observation Of Individual Single Wall Nanotube Species By Raman Microscopy, G. S. Duesberg, W. Blau, Hugh Byrne, J. Muster, M. Burghard, S. Roth Jan 1999

Experimental Observation Of Individual Single Wall Nanotube Species By Raman Microscopy, G. S. Duesberg, W. Blau, Hugh Byrne, J. Muster, M. Burghard, S. Roth

Articles

Individual single-wall carbon nanotubes (SWNT) or small ropes of SWNTs with the same diameter have been characterised by Raman spectroscopy. Highly pure, length-selected SWNTs adsorbed onto substrates designed for surface-enhanced Raman spectroscopy were investigated with a Raman microscope. Various spectra, each with a distinct sharp peak in the radial breathing mode area and four C–C stretching modes could be observed. The modes also showed a strong variation in the relative intensities. In correlation with theoretical predictions this should establish Raman microscopy as a non-destructive nano-technological tool, capable of determining the diameter, symmetry and position of individual SWNTs.


Leading Charm In Hadron-Nucleus Interactions In The Intrinsic Charm Model, Thomas D. Gutierrez, R. Vogt Jan 1999

Leading Charm In Hadron-Nucleus Interactions In The Intrinsic Charm Model, Thomas D. Gutierrez, R. Vogt

Physics

Leading charm hadrons produced in hadron-nucleus interactions cannot be adequately described within the parton fusion model. Recent results on charm baryon production in ∑-A interactions at 330 GeV with the WA89 detector disagree with fusion predictions. Intrinsic heavy quark pairs in the ∑- (dds) wavefunction provide a simple mechanism for producing fast charm hadrons. We calculate leading charm baryon production from ∑-, ∏- and p projectiles in a two component model combining parton fusion with intrinsic charm. Final state D-, ∑ncn0, ≡ncn+, and ∧ncn+ dσ/dxnF …


Applications Of Advanced Software Techniques To Internet And Www Server Development, John A. Brosnan Jan 1999

Applications Of Advanced Software Techniques To Internet And Www Server Development, John A. Brosnan

Theses

We are living in an information age. Never before has so much data been globally available and instantaneously accessible. The main reason for this revolution is the arrival of the Internet; or perhaps more accurately, the World Wide Web(WWW). This thesis discusses the development of Internet and WWW servers and the latest Web technologies including Java, CORBA and Object Databases. It presents the fundamental concepts of server development and aims to study in particular dynamic WWW servers providing multimedia content. From the viewpoint of interoperability, the CORBA multimedia standard is reviewed. The various mechanisms of data storage and retrieval for …


Adventures In Fire Retardancy, Charles A. Wilkie Jan 1999

Adventures In Fire Retardancy, Charles A. Wilkie

Chemistry Faculty Research and Publications

The work of the author's research group on fire retardancy over the past twenty years is reviewed.


Nonlinear Constrained Optimizer And Parallel Processing For Golden Block Line Search, Duc T. Nguyen, Wilson H. Tang, Yeou K. Tung, Hakizumwami B. Runesha Jan 1999

Nonlinear Constrained Optimizer And Parallel Processing For Golden Block Line Search, Duc T. Nguyen, Wilson H. Tang, Yeou K. Tung, Hakizumwami B. Runesha

Civil & Environmental Engineering Faculty Publications

Generalized exponential penalty functions are constructed for the multiplier methods in solving nonlinear programming problems. The non-smooth extreme constraint Gext is replaced by a single smooth constraint Gs by using the generalized exponential function (base a>1). The well-known K.S. function is found to be a special case of our proposed formulation. Parallel processing for Golden block line search algorithm is then summarized, which can also be integrated into our formulation. Both small and large-scale nonlinear programming problems (up to 2000 variables and 2000 nonlinear constraints) have been solved to validate the proposed algorithms.


Time-Resolved Reflection High-Energy Electron Diffraction Study Of The Ge(111)-C(2×8)-(1×1) Phase Transition, Xinglin Zeng, Bo Lin, Ibrahim El-Kholy, Hani E. Elsayed-Ali Jan 1999

Time-Resolved Reflection High-Energy Electron Diffraction Study Of The Ge(111)-C(2×8)-(1×1) Phase Transition, Xinglin Zeng, Bo Lin, Ibrahim El-Kholy, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The dynamics of the Ge(111)-c(2×8)-(1×1) phase transition is investigated by 100-ps time-resolved reflection high-energy electron diffraction. A laser pulse heats the surface while a synchronized electron pulse is used to obtain the surface diffraction pattern. Slow heating shows that the adatoms in Ge(111)-c(2×8) start to disorder at ∼510 K and are converted to a disordered adatom arrangement at 573 K. For heating with 100-ps laser pulses, the Ge(111)-c(2×8) reconstructed adatom arrangement starts to disorder at 584±16K, well above the onset temperature of ∼510 K for the disordering of Ge(111)-c(2×8) observed for slow …


Neural Networks In The Analysis Of Water-Soluble Sulfonylurea Herbicides Using An Lc/Ms, Joseph Michael Pompano Jan 1999

Neural Networks In The Analysis Of Water-Soluble Sulfonylurea Herbicides Using An Lc/Ms, Joseph Michael Pompano

Theses and Dissertations

In this research, a hidden node pruning algorithm was developed for an artificial neural network (ANN) that automatically determined a more efficient size of the hidden layer, caused the ANN to resize itself, and then continued to train using a standard back-propagation algorithm. The hidden-node pruning algorithm was based on determining the number of significant eigenvalues present in the matrix of values produced by the hidden layer, starting with an excessive number of hidden nodes.

Eight sulfonylurea herbicides were used as the target analytes in this study. The ability of an ANN to simplify the sample preparation needed for analysis …


Thermal Plasmaspheric Morphology: Effect Of Geomagnetic And Solar Activity, Mark Anthony Reynolds, G. Ganguli, J.A. Fedder, J. Lemaire, R.R. Meier, D.J. Melendez-Alvira Jan 1999

Thermal Plasmaspheric Morphology: Effect Of Geomagnetic And Solar Activity, Mark Anthony Reynolds, G. Ganguli, J.A. Fedder, J. Lemaire, R.R. Meier, D.J. Melendez-Alvira

Publications

A multispecies kinetic model of the thermal plasma in the plasmasphere is used to predict the spatial dependence of the hydrogen ion and helium ion density and temperature for different levels of geomagnetic and solar activity. The particular convection electric field model chosen is intended for the time intervals between substorms. The plasma density and temperature in the equatorial plane are found to exhibit a local-time variation that is sensitive to the details of the convection electric field. In particular, the parallel temperature increases with altitude and the perpendicular temperature decreases with altitude, except in the postmidnight sector, features that …


Fact Sheet, Yale University Office Of Institutional Research Jan 1999

Fact Sheet, Yale University Office Of Institutional Research

Fact Sheets

No abstract provided.


Circulation, Vol. 6, No. 2, Center For Coastal Physical Oceanography, Old Dominion University Jan 1999

Circulation, Vol. 6, No. 2, Center For Coastal Physical Oceanography, Old Dominion University

CCPO Circulation

Winter 1999 issue of CCPO Circulation featuring article "Identifying Different Flow Constituents in Estuaries"


Frontogenesis In The North Pacific Oceanic Frontal Zones--A Numerical Simulation, Michael S. Dinniman, Michele M. Rienecker Jan 1999

Frontogenesis In The North Pacific Oceanic Frontal Zones--A Numerical Simulation, Michael S. Dinniman, Michele M. Rienecker

CCPO Publications

A primitive equation model [Geophysical Fluid Dynamics Laboratory's (GFDL's) MOM 2] with one degree horizontal resolution is used to simulate the seasonal cycle of frontogenesis in the subarctic frontal zone (SAFZ) and the subtropical frontal zone (STFZ) of the North Pacific Ocean. The SAFZ in the model contains deep (greater than 500 m in some places) regions with seasonally varying high gradients in temperature and salinity. The gradients generally weaken toward the east. The STFZ consists of a relatively shallow (less than 200 m in most places) region of high gradient in temperature that disappears in the summer/fall. The high …


Decadal Variabilities Of The Upper Layers Of The Subtropical North Atlantic: An Ocean Model Study, Tal Ezer Jan 1999

Decadal Variabilities Of The Upper Layers Of The Subtropical North Atlantic: An Ocean Model Study, Tal Ezer

CCPO Publications

Numerical simulations of the Atlantic Ocean during the period 1950 to 1989, using a sigma coordinate, free surface numerical model, show long-term variabilities in the upper ocean subtropical gyre similar to those obtained from observations. The simulations show how westward propagating planetary waves, originated in the eastern North Atlantic, affect interdecadal variabilities of ocean properties such as the Bermuda sea level, the Gulf Stream position and strength, and subsurface temperature anomalies in the western North Atlantic. Special attention is given to the dramatic sea level drop at Bermuda in the early 1970s, which is accompanied by cooling of subsurface layers …


Continental Runoff And Effects On The North Atlantic Ocean Subtropical Mode Water, Larry P. Atkinson, Chester E. Grosch Jan 1999

Continental Runoff And Effects On The North Atlantic Ocean Subtropical Mode Water, Larry P. Atkinson, Chester E. Grosch

CCPO Publications

Interannual salinity variations in North Atlantic Subtropical Mode Water (STMW) are well known although the cause is less well understood. Attempts to model local salinity variation with local evaporation and precipitation have not been successful and some authors invoke advection of low salinity water as the cause. Examination of the STMW and North American river runoff data suggests that runoff may partly explain the salinity variations. It is known that low salinity water resulting from Mississippi River outflow is transported well past Cape Hatteras. Spearman Rank Correlation analysis and spectra and cross-spectra Fourier correlation analysis both show that river flow …


Warm Water Formation And Escape In The Upper Tropical Atlantic Ocean - 1. A Literature Review, Sang-Ki Lee, G. T. Csanady Jan 1999

Warm Water Formation And Escape In The Upper Tropical Atlantic Ocean - 1. A Literature Review, Sang-Ki Lee, G. T. Csanady

CCPO Publications

We review current understanding of the warm water formation and escape process in the tropical Atlantic Ocean and point out the physical aspects of the process not yet fully explored. From this review, we found a need for a simple model capable of describing the first-order heat and mass balance in the tropical Atlantic Ocean. This line of work is continued in part 2 [Lee and Csanady, this issue]. Copyright 1999 by the American Geophysical Union.


Modeling The Effects Of Doliolids On The Plankton Community Structure Of The Southeastern Us Continental Shelf, A. G. Edward Haskell, Eileen E. Hofmann, Gustav-Adolf Paffenhofer, Peter G. Verity Jan 1999

Modeling The Effects Of Doliolids On The Plankton Community Structure Of The Southeastern Us Continental Shelf, A. G. Edward Haskell, Eileen E. Hofmann, Gustav-Adolf Paffenhofer, Peter G. Verity

CCPO Publications

A model of the lower trophic levels that consists of a system of coupled ordinary differential equations was developed to investigate the time-dependent behavior of doliolid populations associated with upwelling features on the outer southeastern US continental shelf. Model equations describe the interactions of doliolids with two phytoplankton size fractions, five copepod developmental stages and a detrital pool. Additional equations describe nitrate and ammonia. Model dynamics are based primarily upon data obtained from field and laboratory experiments for southeastern US continental shelf plankton populations. Variations on a reference simulation, which represents average upwelling conditions without doliolids, were carried out to …


Aquatic Vegetation In Irrigation Canals, Mark Sytsma, Michael Parker Jan 1999

Aquatic Vegetation In Irrigation Canals, Mark Sytsma, Michael Parker

Center for Lakes and Reservoirs Publications and Presentations

Preparation of this guidance manual for integrated aquatic vegetation management in irrigation canals was stimulated, in large part, by the accidental release of acrolein-treated irrigation water into Bear Creek in southern Oregon. The resulting fish kill brought into focus the need to examine the methods available for managing aquatic vegetation in flowing water. Furthermore, it demonstrated the need for technical assistance on aquatic vegetation management in Oregon. Vegetation management in flowing water is a difficult undertaking. The interconnectedness of natural and manmade water conveyance systems, the tenuous status of many aquatic species, and the necessity of water delivery for profitable …


Improved Properties Of Taox Films Doped With Al And N, Robert B. Van Dover, Lynn Schneemeyer, R. M. Fleming, D. J. Werder Jan 1999

Improved Properties Of Taox Films Doped With Al And N, Robert B. Van Dover, Lynn Schneemeyer, R. M. Fleming, D. J. Werder

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Simultaneous addition of Al and N to Ta-O thin films is found to significantly improve the dielectric properties of the films. Specifically, substitution of 10-40 at. % Al for Ta along with approx. 2 at. % N for O is found to decrease the density of catastrophic defects in the films, resulting in high and statistically more uniform breakdown voltages. This conclusion is based on evaluation of approx. 750 individual capacitors in each experiment.


Studies On The Amylolytic Breakdown Of Damaged Starch In Cereal And Non-Cereal Flours, Karen Bailey Jan 1999

Studies On The Amylolytic Breakdown Of Damaged Starch In Cereal And Non-Cereal Flours, Karen Bailey

Masters

The term starch damage refers to a number of changes to the starch granule structure, which are detectable by different analytical techniques. Damaged starch is the substrate for amylases, which in turn provides carbohydrates that are used in the production of certain foods and food ingredients; as a result, therefore, determination of levels in flours is a procedure carried out routinely by many manufacturers of starch based products. Enzymatic assay methods emulate the susceptibility of damaged starch granules to enzymatic attack. The first aim of this study was to evaluate enzymatic methods(1,2) to determine damaged starch in wheat flours and …


Use Of Excel To Obtain Voltammetric Information On Microelectrodes, Enda Howard, John Cassidy Jan 1999

Use Of Excel To Obtain Voltammetric Information On Microelectrodes, Enda Howard, John Cassidy

Articles

The use of curve fitting for the analysis and interpretation of voltammetric data obtained while working with micro electrodes is discussed as a useful exercise for introducing students to the principle of problem solving using least-squares curve-fitting techniques. The advantages associated with this approach to data processing over the approach where the limiting current (i L) alone is used are discussed and its limitations are highlighted. This technique was applied to the determination of unknown concentrations of ferrocyanide and the most satisfactory recovery of concentrations was found when both the va1ues of the formal potential (EO') and concentration ( C) …


A Www Based Software Metrics Environment For Software Process Management And Software Product Quality Improvement, Xiaoqing Frank Liu, Ravi Viswanathan Jan 1999

A Www Based Software Metrics Environment For Software Process Management And Software Product Quality Improvement, Xiaoqing Frank Liu, Ravi Viswanathan

Computer Science Faculty Research & Creative Works

The software process needs to be continuously improved to develop high quality software. However, with increasing specialization in the workforce and decentralization in the workplace, software process planning, monitoring, analysis and dynamic tuning in a heterogeneous distributed environment becomes a challenge. We describe a tool which takes advantage of emerging Internet technology to implement a software metrics environment for software process management and software quality improvement. The tool uses a dimensional analytic model to visualize the software development process. The system offers facilities to monitor the status and quality attributes of projects being developed at multiple sites and on multiple …


The Revovery Of Copper And Cobalt From Oxidized Copper Ore And Converter Slag, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari Jan 1999

The Revovery Of Copper And Cobalt From Oxidized Copper Ore And Converter Slag, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari

Turkish Journal of Chemistry

The aim of this study was to develop a method for obtaining copper and cobalt from oxidized copper ore and converter slag. In order to convert the copper and cobalt into sulfate compounds the main step was to roast the samples obtained by sulfurization and transfer the samples into solution. First the oxidized copper ore was roasted, followed by the mixture of converter slag and oxidized copper ore. Since the levels of copper and cobalt were low, the sulfurization process was carried out under autoclave conditions. The samples obtained were roasted. The yields of copper and cobalt passed into the …


Developing Database Applications By Using Software Components, Nusret Conk Jan 1999

Developing Database Applications By Using Software Components, Nusret Conk

College of Graduate Studies: Theses & Dissertations (1964–2006)

Today, the software application development process is more assembly work than a "build from scratch" approach. By placing pre-existing software components together, it is possible to create a complete application. Such components provide interfaces so that programs use them for their intended purposes. The objective of this thesis is to illustrate how software components work together to make a complete application. To illustrate the ideas and the components, this project presents a three-tiered web database application. This application, as a whole, is made up of the client side web browser, a database and the actual application programs which are Java …


The Development And Validation Of A Methodology For The Analysis Of Polyaromatic Hydrocarbons In Air Particulates (Indoor And Outdoor), Kathryn O'Malley Jan 1999

The Development And Validation Of A Methodology For The Analysis Of Polyaromatic Hydrocarbons In Air Particulates (Indoor And Outdoor), Kathryn O'Malley

Masters

PAH form a large class of ubiquitous pollutants mainly of anthropogenic origin. Several PAH found in air particulates have been identified as carcinogens and mutagens. Sixteen of these PAH have been listed by the USEPA as priority pollutants. This research is concerned with the development and optimisation of a method for the analysis of these sixteen PAH in air particulates. Soxhlet and ultrasonic extraction procedures were investigated to optimise the recoveries from spiked glass fibre filters with a standard 1ppm mixture of the 16PAH. Standard mixtures of the 16 PAH were analysed by HPLC with fluorescence detection with approx. linearity …


The Impacts Of External Nutrient Sources On Marine Phytoplankton In An Eastern Shore Sea-Side Estuary, Claudette Lajoie Jenkins Jan 1999

The Impacts Of External Nutrient Sources On Marine Phytoplankton In An Eastern Shore Sea-Side Estuary, Claudette Lajoie Jenkins

OES Theses and Dissertations

The Eastern Shore of Virginia (Greens Creek) as well as a large portion of the North Atlantic coastline is characterized by estuarine systems not dominated by large river systems. Instead, small freshwater creeks influence many coastal systems yet little information has been documented on their ecological significance. The focus of this research is to identify the biogeochemical and physical interactions within an estuarine water-column and understand the importance of freshwater sources in governing phytoplankton production. The hypothesis of this research is that increases in external nutrient loading into Greens Creek will not result in an increase in primary production. The …


Effect Of The Environmental Parameters On The Distribution Of Foraminifera In The Coastal Area Of Ras Al Khaimah, U.A.E., Naama Obaid Saif Al-Kaabi Jan 1999

Effect Of The Environmental Parameters On The Distribution Of Foraminifera In The Coastal Area Of Ras Al Khaimah, U.A.E., Naama Obaid Saif Al-Kaabi

Theses

Twenty samples of sea water and twenty samples of sediment were collected from the off shore area of Ras AI-Khaimah to find out the relationships between environmental parameters, abundance of foraminifera, and ratio of living to dead foraminifera.

Analysis of sea water for the environmental parameters includs, temperature, salinity and nutrient salts (nitrate, nitrite, silicate, phosphate and amonia). Organic mattar, and total carbonate were measured in the bottom sediments. Grain size analysis of the bottom sediments was done using seiving method. The foraminiferal species were picked, counted and photographed using the SEM. The ratio of dead to living forams was …


User-Responsivity And Environment-Sensitivity Consideration For State-Funded Housing In Alain City, Nassra Saif Al Daheri Jan 1999

User-Responsivity And Environment-Sensitivity Consideration For State-Funded Housing In Alain City, Nassra Saif Al Daheri

Theses

Massive housing projects have shown that prospective users are rarely given the opportunity to participate in the design decisions. Subsequently, such schemes commonly fail to accommodate all their needs. In the Emirate of Abu Dhabi, the housing projects that aim at resettling of Bedouin into newly developed urban communities are state-funded. Many of these houses that were built in the late seventies and early eighties were transferred back to the state (in a very bad condition due to the users random modifications and additions) in exchange of newer better houses. The lack of an adaptive design concept that can accommodate …


Optimisation Studies In A Batch Pharmaceutical Company, Sarah Fitzgerald Jan 1999

Optimisation Studies In A Batch Pharmaceutical Company, Sarah Fitzgerald

Theses

This thesis outlines a collaborative project between industry and academia based on a short term research contract.

In the past in Eli Lilly, process optimisation in a multi-purpose, modular building had been mainly confined to equipment commissioning and new product development. It was necessary to embark upon an exercise to develop an optimisation programme m order to meet the increased requirements and demands of the building. Increased market demands, through the introduction of over-the-counter (OTC) drugs, and the demand for cycle time reduction through the expiry of existing patents, made the need for optimisation inevitable.

The purpose of this thesis …


Enterprise Business Objects : Design And Implementation Of A Business Object Framework, Kai-Uwe Schafer Jan 1999

Enterprise Business Objects : Design And Implementation Of A Business Object Framework, Kai-Uwe Schafer

Theses

Software components representing business entities like customer or purchase order introduce a new way of Online Transaction Processing to business applications. Collaborating business objects allow to complete whole business processes as a single distributed transaction, instead of dividing it into queued steps, which sometimes even require user intervention. This IS due to the fact that business objects contain both business data and logic and that they incorporate multiple databases from different vendors and different geographic locations in a single transaction.

Business objects cannot be used as stand-alone components, but require a framework of services that manage persistence, concurrent transactions, and …


Characterisation And Optimisation Of Gypsum Crystallization, Catherine H. Shannon Jan 1999

Characterisation And Optimisation Of Gypsum Crystallization, Catherine H. Shannon

Theses

Gypsum is produced as a by-product during the citric acid production process at ADM Ringaskiddy. The particle size and filterability of the gypsum has a critical bearing on the overall citric acid production rate. Prior to August 1996, research in the area of gypsum crystal optimisation at ADM had concentrated on the application of vortex mixing to perform the gypsum formation reaction. While the gypsum crystals produced with vortex mixing were found to be desirably clear of microcrystalline gypsum, the crystals were considerably smaller and more difficult to filter and wash. This research project sought to retain the advantages conferred …


The Atomic Force Microscope In The Elucidation Of Leukocyte Abnormality, Derbrenn O'Connor Jan 1999

The Atomic Force Microscope In The Elucidation Of Leukocyte Abnormality, Derbrenn O'Connor

Theses

The aim of this project was to investigate the novel use of the atomic force microscope (AFM) as a technique in the elucidation of leukocyte abnormality. To this end, comparative AFM imaging and elasticity studies were performed on normal and myeloid leukaemic leukocytes.

Initially, an evaluation of techniques for the isolation of specific leukocyte (e.g. lymphocytes, granulocytes, etc.) populations from whole blood or leukocyte concentrates, was carried out. It was found that a silanised glass surface failed to select and immobilise a leukocyte population. However, centrifugation of whole blood in an Isopaque-ficoll gradient solution yielded a viable mixed leukocyte population …