Physical Sciences and Mathematics Commons^™

The Synthesis And Characterisation Of Diiron And Triiron Carbonyl Cluster Compounds With Sulphur And Phosphine Ligands, Geraldine Gray

Theses

This work is primarily concerned with the synthesis and characterisation of di and triiron carbonyl cluster derivatives which contain sulphur and phosphine ligands.

The first chapter is a review of the literature of such complexes. Included are diiron carbonyl clusters which contain phosphine ligands, those which contain sulphur, and those that contain phosphine and sulphur ligands. Triiron carbonyl clusters which contain phosphine ligands, sulphur ligands and both are also discussed.

Chapter two describes the synthesis of compounds of the type [{Fe₂(SR)₂(CO)₅)₂Ph₂P (CH₂)_nPPh₂] (R = …

Development Of Electrochemical Sensors For Monitoring Glucose, Michael Nesbitt

Theses

The thesis focuses on evaluating calcium alginate as an immobilisation matrix for the oxidase enzyme glucose oxidase for the amperometric determination of glucose. The basic principles of enzymology and enzyme immobilisation is discussed followed by a review of a variety of first, second and third generation type enzyme electrodes. Amperometry as governed by the Cottrell equation and mass transfer models relating to amperometric electrodes are also considered.

Bovine serum albumin (BSA / GOx) enzyme electrode system was employed as a model to evaluate a calcium alginate immobilisation technique for glucose oxidase. The principal methods employed for enzyme immobilisation were:

• …

A High Precision Radial Velocity Survey Of K Giants, David S. Mitchell

Physics

Precise radial velocity measurements of stars can provide a powerful tool for both examining the intrinsic atmospheric activity of the star, and testing for the existence of substellar orbital companions. This method has been used to detect the vast majority of known extrasolar planets, as well as probing the asteroseismological characteristics of active stars. This dissertation presents the results of a precise radial velocity survey of 177 bright K giant stars. Six of the stars have data that indicate the presence of planetary or brown dwarf orbital companions. Many others have evidence of nonradial pulsations, and twenty binary stars are …

Development And Climate Change In Egypt: Focus On Coastal Resources And The Nile, Shardul Agrawala, Annett Moehner, Mohamed El Raey, Declan Conway, Maarten Van Aalst, Marca Hagenstad, Joel Smith

Egypt & Libya

This report presents the integrated case study for Egypt carried out under an OECD project on Development and Climate Change. The report is structured around a three-tiered framework. First, recent climate trends and climate change scenarios for Egypt are assessed and key sectoral impacts are identified and ranked along multiple indicators to establish priorities for adaptation. Second, donor portfolios are analyzed to examine the proportion of development assistance activities affected by climate risks. A desk analysis of donor strategies and project documents as well as national plans is conducted to assess the degree of attention to climate change concerns in …

Correction To "Breaking Of Thunderstorm-Generated Gravity Waves As A Source Of Short-Period Ducted Waves At Mesopause Altitudes", Jonathan B. Snively, Victor P. Pasko

Publications

No abstract provided.

Fact Sheet, Yale University Office Of Institutional Research

Fact Sheets

No abstract provided.

Modeled And Observed Empirical Orthogonal Functions Of Currents In The Yucatan Channel, Gulf Of Mexico, Lie-Yauw Oey, Tal Ezer, Wilton Sturges

CCPO Publications

Candela et al. [2003] have reported empirical orthogonal function (EOF) analyses based on 23-month current-meter and acoustic Doppler current profiler measurements in the Yucatan Channel. Those authors noted the difference between EOFs obtained from observations and their z-level models and EOFs calculated by Ezer et al. [2003] from the results of a terrain-following model. Here a new analysis is reported that explains this difference, and that also suggests the importance of shelf-edge meander mode of the core Loop Current in the channel. We show that the terrain-following model gives EOFs with characteristics similar to those observed when data from the …

Numerical Study Of The Diapycnal Flow Through A Tidal Front With Passive Tracers, Chingming Dong, Robert Houghton, Hsien-Wang Ou, Dake Chen, Tal Ezer

CCPO Publications

A two-dimensional numerical model is used to study the diapycnal flow through a tidal front with passive tracers. In a basic numerical experiment a passive tracer is released into the bottom water at the offshore edge of a tidal front, and it subsequently moves on-bank with a velocity that decreases with time. This qualitatively agrees with a recent field experiment using a dye tracer on Georges Bank. Additional experiments are performed to investigate the sensitivity of the tracer dispersion to the tidal phase and the location of tracer release within the front. As the release point is moved on-bank across …

Simulations Of The Influence Of The West Caribbean Sea Circulation And Eddies On The Meso-American Barrier Reef System, Tal Ezer, Deeptha V. Thattai, Björn Kjerve

CCPO Publications

The Meso-American Barrier Reef System (MBRS) along the coasts of Mexico, Belize, Guatemala, and Honduras is an ecologically and biologically sensitive region. It provides for example, major spawning aggregation sites for various species of fish; these activities may be influenced by variations of the flow near the reef and the transports between the MBRS and the Caribbean Sea circulation. Caribbean eddies, which may play an important role in flow variability, have been studied in the past by observations and models (Carton and Chao, 1999; Murphy et al., 1999; Andrade and Barton, 2000; Oey et al., 2003), but knowledge of their …

On The Sensitivity Of The West Caribbean Sea Circulation To Tides, Wind, And Mesoscale Ocean Eddies: A Three-Dimensional Ocean Model Study, Deeptha V. Thattai, Tal Ezer, Bjorn Kjerfve

CCPO Publications

A three-dimensional, primitive equation ocean model is used to study the circulation in the West Caribbean Sea (WCS) region, and to test the sensitivity of the coastal flow to various forcing fields such as tides, climatological wind, and Caribbean eddies. The model domain is bordered by latitudes 15 – 22 degrees N and longitudes 76 – 87 degrees W, with the MesoAmerican Barrier Reef System (MBRS, along the coasts of Mexico, Belize, Guatemala, and Honduras) and the southern coast of Cuba as land boundaries. The WCS is open to the Caribbean Sea in the southeast and the Yucatan Channel in …

Advection, Krill, And Antarctic Marine Ecosystems, Eileen E. Hofmann, Eugene J. Murphy

CCPO Publications

Advective processes are recognized as being important in structuring and maintaining marine ecosystems. In the Southern Ocean advective effects are perhaps most clearly observed because the Antarctic Circumpolar Current (ACC) provides a connection between most parts of the system, including open ocean and continental shelf regions. The ACC also provides a mechanism for large-scale transport of plankton, such as Antarctic krill (Euphousia superba Dana), which is an important component of the Southern Ocean food web. This overview provides a summary of recent observational and modelling results that consider the importance of advection to the Southern Ocean ecosystem and, in particular, …

Satellite Evidence Of Hurricane-Induced Phytoplankton Blooms In An Oceanic Desert, S. M. Babin, J. A. Carton, T. D. Dickey, J. D. Wiggert

CCPO Publications

The physical effects of hurricanes include deepening of the mixed layer and decreasing of the sea surface temperature in response to entrainment, curl-induced upwelling, and increased upper ocean cooling. However, the biological effects of hurricanes remain relatively unexplored. In this paper, we examine the passages of 13 hurricanes through the Sargasso Sea region of the North Atlantic during the years 1998 through 2001. Remotely sensed ocean color shows increased concentrations of surface chlorophyll within the cool wakes of the hurricanes, apparently in response to the injection of nutrients and/or biogenic pigments into the oligotrophic surface waters. This increase in post-storm …

Greening Connecticut Cities And Towns, Managing Public Trees And Community Forests, Glenn D. Dreyer, Robert M. Ricard

Other Publications and Reports

No abstract provided.

Activators Of Luminescence In Speleothems As Source Of Major Mistakes In Interpretation Of Luminescent Paleoclimatic Records, Y. Y. Shopov

International Journal of Speleology

This work summarizes the main results of the operation of the International Program “Luminescence of Cave Minerals” of the commission on Physical Chemistry and Hydrogeology of Karst of UIS of UNESCO in the field of activators of speleothem luminescence. It discusses Activators of Luminescence in Speleothems as a source of major mistakes in the interpretation of luminescent paleoclimatic records. It demonstrates the existence of 6 types of luminescence of speleothems and cave minerals in dependence of the type of the luminescence center and its incorporation in the mineral. 24 different activators of photoluminescence of speleothem calcite and 11 of aragonite …

Trace Elements In Speleothems. A Short Review Of The State Of The Art, Sophie Verheyden

International Journal of Speleology

A state of the art of the research on trace elements of speleothems is given. First studies focussed on problems such as the colour of speleothems and the aragonite problem. Insitu studies and studies oriented towards a better understanding of vadose hydrology brought new insights in the controls on trace elemental composition of speleothems. Recent studies deal with microscale analyses and annual and intra-annual chemistry changes. Further in-situ studies should be performed to further differentiate influences, such as climate, soil/weathering and local hydrology in order to better constrain possible transfer functions between the surface and a speleothem.

Crash Analysis: An Investigation Of Current Speed Estimation Techniques, Robert Rice

Masters

The increasing number of cars and collisions on the roads of Europe ensure that the need for accurate speed estimation is an ever-more pressing requirement. This requirement has provided the motivation for an investigation into the accuracy and reliability of existing crash models An in-depth literature review was undertaken to create a greater understanding of the structural collapse behaviour of vehicles during full frontal collisions. It was decided to concentrate the work on frontal collisions as this type of accident makes up the majority of road accidents. This review underlined some of the phenomena that need to be considered when …

Openmvc: A Non-Proprietary Component-Based Framework For Web Applications, Ronan Barrett, Sarah Jane Delany

Conference papers

No abstract provided.

Photonic Band Gap Analysis Using Finite-Difference Frequency-Domain Method, Shangping Guo, Feng Wu, Sacharia Albin

Electrical & Computer Engineering Faculty Publications

A finite-difference frequency-domain (FDFD) method is applied for photonic band gap calculations. The Maxwell’s equations under generalized coordinates are solved for both orthogonal and non-orthogonal lattice geometries. Complete and accurate band gap information is obtained by using this FDFD approach. Numerical results for 2D TE/TM modes in square and triangular lattices are in excellent agreements with results from plane wave method (PWM). The accuracy, convergence and computation time of this method are also discussed.

Sources And Cycling Of Carbonyl Sulfide In The Sargasso Sea, Gregory A. Cutter, Lynda S. Cutter, Katherine C. Filippino

OES Faculty Publications

The cycling of the radiatively important gas carbonyl sulfide (OCS) was studied in surface waters of the Sargasso Sea. In August 1999, surface OCS concentrations averaged 8.6 pmol L^-1, showed minor diel variations, and varied little with depth. An OCS precursor, total dissolved organic sulfur (DOS), was lowest at the surface (40 nmol L^-1) and increased with depth. The photoproduction rate of OCS from in situ incubations averaged 9.6 pmol L^-1 h^-1, whereas dark production was 7.0 pmol L^-1 h^-1. Apparent quantum yields were 10^-5-10^-7 from 313-436 …

Analytical Intercomparison Between Flow Injection-Chemiluminescence And Flow Injection-Spectrophotometry For The Determination Of Picomolar Concentrations Of Iron In Seawater, Andrew R. Bowie, Peter N. Sedwick, Paul J. Worsfold

OES Faculty Publications

A lab- and ship-based analytical intercomparison of two flow injection methods for the determination of iron in seawater was conducted, using three different sets of seawater samples collected from the Southern Ocean and South Atlantic. In one exercise, iron was determined in three different size-fractions (< 0.03 &μm, < 0.4 μm, and unfiltered) in an effort to better characterize the operational nature of each analytical technique with respect to filter size. Measured Fe concentrations were in the range 0.19 to 1.19 nM using flow injection with luminol chemiluminescence detection (FI-CL), and 0.07 to 1.54 nM using flow injection with catalytic spectrophotometric detection with N, N-dimethyl-p-phenylenediamine dihydrochloride (FI-DPD). The arithmetic mean for the FI-CL method was higher (by 0.09 nM) than the FI-DPD method for dissolved (< 0.4 μm) Fe, a difference that is comparable to the analytical blanks, which were as high as 0.13 nM ( CL) and 0.09 nM (DPD). There was generally good agreement between the FI-CL determinations for the < 0.03 μm size fraction and the FI-DPD determinations for the < 0.4 μm size fraction in freshly collected samples. Differences in total-dissolvable ( unfiltered) Fe concentrations determined by the two FI methods were more variable, reflecting the added complexity associated with the analysis of partially digested particulate material in these samples. Overall, however, the FI-CL determinations were significantly (P = 0.05) lower than the FI-DPD determinations for the unfiltered samples. Our results suggest that the observed, systematic inter-method differences reflect measurement of different physicochemical fractions of Fe present in seawater, such that colloidal and/or organic iron species are better determined by the FI-CL method than the FI-DPD method. This idea is supported by our observation that inter-method differences were largest for freshly collected acidified seawater, which suggests extended storage (>6 months) of acidified samples as a possible protocol for the determination of dissolved iron in seawater.

Physical Forcing Of Phytoplankton Community Structure And Primary Production In Continental Shelf Waters Of The Western Antarctic Peninsula, Barbara B. Prézelin, Eileen E. Hofmann, Mark Moline, John M. Klinck

OES Faculty Publications

Analyses of a multidisciplinary data set, collected in continental shelf waters of the Western Antarctic Peninsula (WAP) during austral summer of January 1993, identified a previously unrecognized forcing mechanism that sets up a physical and chemical structure that supports and assures site-specific diatom-dominated communities and enhanced biological production (Prézelin et al., 2000). This forcing is active when the southern boundary of the Antarctic Circumpolar Current (ACC) flows along the shelf edge, thereby facilitating onshelf bottom intrusions of nutrient-rich Upper Circumpolar Deep Water (UCDW), which then is upwelled or mixed into the upper water column. At times or locations where UCDW …

Black Carbon In Estuarine And Coastal Ocean Dissolved Organic Matter, Antonio Mannino, H. Rodger Harvey

OES Faculty Publications

We measured black carbon (BC) in ultrafiltered, high-molecular weight dissolved organic matter (UDOM) in surface waters of Delaware Bay, Chesapeake Bay, and the adjacent Atlantic Ocean (U.S.A.) to investigate the importance of riverine and estuarine dissolved organic matter (DOM) as a source of BC to the ocean. BC was 5-72% of UDOM-C (27 ± 17%), which corresponds to 8.9 ± 6.5% of dissolved organic carbon (DOC), with higher values in the heavily urbanized midbay region of the Delaware Estuary and lower yields in the river and coastal ocean. The spatial and seasonal distributions of BC along the salinity gradient of …

Relevant Scales In Zooplankton Ecology: Distribution, Feeding, And Reproduction Of The Copepod Acartia Hudsonica In Response To Thin Layers Of The Diatom Skeletonema Costatum, Alexander B. Bochdansky, Stephen M. Bollens

OES Faculty Publications

We investigated the interaction of the copepod Acartia hudsonica in relation to thin layers of the diatom Skeletonema costatum. Thin layers have recently received much attention, since they are common and persistent features in the water column, often overlooked by traditional sampling methods. Their frequent abundance in coastal oceans and the high biomass associated with them has led to the assumption that they are important grazing sites of calanoid copepods. We employed 2-m tall tower tanks that allowed us to simulate thin layers. Three variables representative of three time scales were considered: the distribution of copepods in the tanks …

Potential Contaminants At A Dredged Spoil Placement Site, Charles City County, Virginia, As Revealed By Sequential Extraction, Jianwu Tang, G. Richard Whittecar, Karen H. Johannesson, W. Lee Daniels

OES Faculty Publications

Backfills of dredged sediments onto a former sand and gravel mine site in Charles City County, VA may have the potential to contaminate local groundwater. To evaluate the mobility of trace elements and to identify the potential contaminants from the dredged sediments, a sequential extraction scheme was used to partition trace elements associated with the sediments from the local aquifer and the dredged sediments into five fractions: exchangeable, acidic, reducible, oxidizable, and residual phases. Sequential extractions indicate that, for most of the trace elements examined, the residual phases account for the largest proportion of the total concentrations, and their total …

Interactive Regulation Of Dissolved Copper Toxicity By An Estuarine Microbial Community, Christina L. Dryden, Andrew S. Gordon, John R. Donat

OES Faculty Publications

Cultured marine microorganisms under copper stress produce extracellular compounds having a high affinity for copper (copper-complexing ligands). These ligands are similar in binding strength to those found in natural waters, but few studies have examined the relationship between copper, copper-complexing ligand concentrations, and natural microbial populations. A series of in situ experiments in the Elizabeth River, Virginia, revealed that an intact estuarine microbial community responded to copper stress by production of extracellular, high-affinity copper-complexing ligands. The rate of ligand production was dependent on copper concentration and resulted in a reduction of the concentration of free cupric ions, Cu²⁺, …

Dinitrogen Fixation And Release Of Ammonium And Dissolved Organic Nitrogen By Trichodesmium Ims101, Margaret R. Mulholland, Deborah A. Bronk, Douglas G. Capone

OES Faculty Publications

Two methods used to measure dinitrogen (N₂) fixation (acetylene reduction and ¹⁵N₂ uptake) often result in different N₂ fixation rates. Part of the discrepancy may arise from the observation that Trichodesmium can release a fraction of their recently fixed N₂ as dissolved organic nitrogen (DON) and/or ammonium (NH4 ⁺). To resolve outstanding issues regarding N₂ fixation and the production of dissolved combined nitrogen (N) by Trichodesmium, we conducted a comprehensive analysis of N₂ fixation and the production of DON and NH₄⁺ in cultures of Trichodesmium IMS101. We performed …

Age And Growth Of Scotia Sea Icefish, Chaenocephalus Aceratus, From The South Shetland Islands, M. La Mesa, J. Ashford, E. Larson, M. Vacchi

OES Faculty Publications

Samples of Chaenocephalus aceratus (Lönnberg) were collected during a trawl survey carried out around the South Shetland Islands in January–February 2002. Fish were caught by commercial bottom trawl fishing down to 500 m depth, using a stratified randomized sampling design. As observed in other recent surveys within the same area, C. aceratus represented one of the predominant species. Overall, 357 specimens ranging from 13 and 67 cm (TL) were selected for the present study. Ages were estimated by counting annuli present in the sagittal otoliths, exposed by grinding and polishing along their sagittal plane. To estimate the precision of age …

A Holocene Record Of Changing Arctic Ocean Ice Drift Analogous To The Effects Of The Arctic Oscillation, Dennis A. Darby, Jens F. Bischof

OES Faculty Publications

The Arctic Oscillation (AO) controls the configuration of the Transpolar Drift (TPD). If thicker ice from the Beaufort Gyre were exported, the volume of fresh water/sea ice in the Nordic seas would significantly increase, decreasing the formation of North Atlantic deep water. This would cool large parts of the Northern Hemisphere and affect global climate. Therefore, in order to understand how the global climate system functions, it is imperative to know how the TPD changed over the last millennium or more. The provenance of grains in a sediment core located near the confluence of the TPD and the Beaufort Gyre …

Integrating Perception, Language And Problem Solving In A Cognitive Agent For A Mobile Robot., Deryle W. Lonsdale, D. Paul Benjamin, Damian M. Lyons

Faculty Publications

We are implementing a unified cognitive architecture for a mobile robot. Our goal is to endow a robot agent with the full range of cognitive abilities, including perception, use of natural language, learning and the ability to solve complex problems. The perspective of this work is that an architecture based on a unified theory of robot cognition has the best chance of attaining human-level performance.

This agent architecture is an integration of three theories: a theory of cognition embodied in the Soar system, the RS formal model of sensorimotor activity and an algebraic theory of decomposition and reformulation.

These three …

Influence Of Antenna Aiming On Ece In Mast, Josef Preinhaelter, Jakub Urban, Pavol Pavlo, Vladimir Shevchenko, Martin Valovič, Linda L. Vahala, George Vahala

Electrical & Computer Engineering Faculty Publications

The effect of the direction of the detected beam on the intensity of ECE is studied. It is found that the combined effects of the strong dependence of the conversion efficiencey of O mode at the plasma resonance on the direction of the incident wave and the partial screening of the beam waist by the MAST vessel wall, can be responsible for the weakening of ECE emission for some frequencies. The theoretical model for ECE data interpretation on MAST has been significantly improved. New features of the model are as follows: the quasioptical treatment of the receiving antenna, interference, polarization …