Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2008

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 12661 - 12690 of 13177

Full-Text Articles in Entire DC Network

The Kinetics And Mechanism Of Ruthenium(Iii)-Catalyzed Oxidation Of Tris(2-Amino Ethyl)Amine By Hexacyanoferrate(Iii) In Aqueous Alkaline Medium, Radhey Mohan Naik, Abhishek Srivastava, Amit Kumar Verma Jan 2008

The Kinetics And Mechanism Of Ruthenium(Iii)-Catalyzed Oxidation Of Tris(2-Amino Ethyl)Amine By Hexacyanoferrate(Iii) In Aqueous Alkaline Medium, Radhey Mohan Naik, Abhishek Srivastava, Amit Kumar Verma

Turkish Journal of Chemistry

The kinetics of ruthenium(III)-catalyzed oxidation of TREN, i.e. tris(2-amino ethyl)amine(3-hydrochloride) by an outer sphere electron transfer oxidant, potassium hexacyanoferrate(III), was investigated spectrophotometrically in aqueous alkaline medium. The extent of the reaction was followed by registering a decrease in absorbance at 420 nm (\lambda_{max} of Fe(CN)_6^{3-}) due to its consumption as a function of [OH^-], ionic strength, [Fe(CN)_6^{3-}], [TREN], and temperature by varying only one variable at a time and keeping all other variables constant. The rate data indicate that the reaction exhibited first order dependence in [oxidant] and at a lower concentrations of reductant. The overall reaction follows second order …


Cover And Contents Jan 2008

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.


On-Line Incorporation Of Cloud Point Extraction In Flame Atomic Absorption Spectrometric Determination Of Silver, Nasser Dalali, Nasrin Javadi, Yadvendra Kumar Agawal Jan 2008

On-Line Incorporation Of Cloud Point Extraction In Flame Atomic Absorption Spectrometric Determination Of Silver, Nasser Dalali, Nasrin Javadi, Yadvendra Kumar Agawal

Turkish Journal of Chemistry

A cloud point extraction method was incorporated into a flow injection system, coupled with flame atomic absorption spectrometry, for determination of trace amounts of silver. The analyte in the aqueous solution was acidified with 0.2 mol L^{-1} sulfuric acid and complexed with dithizone. The cloud point extraction was performed using the non-ionic surfactant Triton X-114. After obtaining the cloud point, the surfactant-rich phase containing the dithizonate complex was collected in a mini-column packed with cotton wool. Then the complex was eluted by passing THF through the column and silver content was determined by flame atomic absorption spectrometry. All the chemical …


Synthesis And Antifungal Activity Of Some Novel N-(4-Phenyl-3-Aroylthiazol-2(3h)-Ylidene) Substituted Benzamides, Aamer Saeed, Sabah Zaman, Maryam Jamil, Bushra Mirza Jan 2008

Synthesis And Antifungal Activity Of Some Novel N-(4-Phenyl-3-Aroylthiazol-2(3h)-Ylidene) Substituted Benzamides, Aamer Saeed, Sabah Zaman, Maryam Jamil, Bushra Mirza

Turkish Journal of Chemistry

Variously substituted N-(4-phenyl-3-aroylthiazol-2(3H)-ylidene)benzamides (2a-t) were prepared by base-catalyzed cyclization of corresponding 1-aroyl-3-aryl thioureas with acetophenone in the presence of bromine. Some of the synthesized compounds were assayed in vitro for their antifungal activity and were found to exhibit low to moderate activity.


Hydrogenation Of Citral Over Ni And Ni-Sn Catalysts, Hi̇lal Aykaç, Selahatti̇n Yilmaz Jan 2008

Hydrogenation Of Citral Over Ni And Ni-Sn Catalysts, Hi̇lal Aykaç, Selahatti̇n Yilmaz

Turkish Journal of Chemistry

Liquid phase citral hydrogenation over zeolite-supported monometallic Ni and bimetallic Ni-Sn catalysts was studied. The zeolite support materials were Na-Y, Na-mordenite, and clinoptilolite. Ni and Sn contents of the monometallic and bimetallic catalysts were 8.1-9.2 wt% and 0.46 wt%, respectively. The type of the zeolite support affected the activity and selectivity of the catalysts differently. The main product of the citral hydrogenation reaction was citronellal, for both monometallic (84.5% yield) and bimetallic (44.5% yield) catalysts. The addition of promoter increased the selectivity to unsaturated alcohols (geraniol+nerol), i.e. it changed from 0.9% to 6.3% over mordenite and from 0.9% to 2.1% …


High Yielding Oxidative Deprotection Of Silyl And Pyranyl Ethers To Their Corresponding Carbonyl Compounds With Strontium Manganate In The Presence Of Aluminium Chloride In Solution And Under Solvent-Free Conditions, Mostafa Gholizadeh, I. Mohmmadpoor Baltork Jan 2008

High Yielding Oxidative Deprotection Of Silyl And Pyranyl Ethers To Their Corresponding Carbonyl Compounds With Strontium Manganate In The Presence Of Aluminium Chloride In Solution And Under Solvent-Free Conditions, Mostafa Gholizadeh, I. Mohmmadpoor Baltork

Turkish Journal of Chemistry

Strontium manganate (SrMnO_4) in the presence of aluminium chloride (AlCl_3) is an efficient reagent for the high yielding oxidative deprotection of aromatic and aliphatic silyl and pyranyl ethers into their corresponding carbonyl compounds, in solution and under solvent-free conditions.


Preparation Of Palladium Composite Membranes On Pore Structure Modified And Non-Modified Supports By Electroless Plating Procedure, Sali̇ha Kiliçarslan, Osman Muzaffer Afyon, Meltem Doğan Jan 2008

Preparation Of Palladium Composite Membranes On Pore Structure Modified And Non-Modified Supports By Electroless Plating Procedure, Sali̇ha Kiliçarslan, Osman Muzaffer Afyon, Meltem Doğan

Turkish Journal of Chemistry

The effects of pore structure of the support on the plating morphology, thickness, and composition were investigated in an electroless plating procedure. Some of the plating studies were carried out directly on commercially available porous glass supports, while others were performed on modified supports. Two modification steps with alumina were applied on tubular supports. Formation of a 60-\mu m-thick layer on the modified support was detected by SEM analysis after the first 2 plating steps, while layer formation was not observed on the non-modified support. It was shown that the formation of a new layer started on the modified support, …


Synthesis And Biological Activity Of Allosteric Modulators Of Gaba_B Receptors. Part 4. Synthesis Of Potentially Fluorescent Acridines And Conformationally Restricted N-(Arylpropyl)-1-Arylethylamines, Jabbar Khalafy, Rolf H. Prager, Ni Made Puspawati Jan 2008

Synthesis And Biological Activity Of Allosteric Modulators Of Gaba_B Receptors. Part 4. Synthesis Of Potentially Fluorescent Acridines And Conformationally Restricted N-(Arylpropyl)-1-Arylethylamines, Jabbar Khalafy, Rolf H. Prager, Ni Made Puspawati

Turkish Journal of Chemistry

A series of 8 new derivatives of fendiline was prepared for evaluation as allosteric modulators of GABA_B receptors: 4 based on acridine and 4 with restricted distance between the 2 aryl moieties.


Examination Of The Electroanalytic Performance Of Carbon Nanotube (Cnt) Modified Carbon Paste Electrodes As Xanthine Biosensor Transducers, Ülkü Anik, Meli̇ha Çubukçu Jan 2008

Examination Of The Electroanalytic Performance Of Carbon Nanotube (Cnt) Modified Carbon Paste Electrodes As Xanthine Biosensor Transducers, Ülkü Anik, Meli̇ha Çubukçu

Turkish Journal of Chemistry

The effect of multi-walled carbon nanotube (MWCNT) and single-wall carbon nanotube (SWCNT) on carbon paste electrode (CPE) electrochemical response was examined by introducing various portions of CNT into the CPE. The optimum electrode structure was determined by comparing the prepared electrodes´ electroanalytical performance towards ferricyanide. Then these optimum compositions were modified with xanthine oxidase (XO) enzyme for obtaining a xanthine biosensor. After the optimization of biosensor working conditions, the developed systems were characterized for xanthine. Linearity was obtained in the concentration range between 1 and 100 \mu M xanthine with an RSD value of 3.35% for MWCNT-CPE, while with SWCNT-CPE …


Inequalities And Exponential Approximations For Residual Life Reliability Functions, Broderick O. Oluyede, Marvis Pararai Jan 2008

Inequalities And Exponential Approximations For Residual Life Reliability Functions, Broderick O. Oluyede, Marvis Pararai

Mathematical Sciences: Faculty Publications

Given that a unit is of age t, the remaining life after time t is random. The expected value of this random residual life is called the mean residual life at time t. Specifically, if T is the life of a component with distribution function F, then δF (t) = E(T −t|T > t) is called the mean residual life function (MRLF). It is well known that the class of distributions with decreasing mean residual life (DMR) contains the class of distributions with increasing hazard rate (IHR). In this note, …


A Note On Extreme Bernoulli And Dependent Families Of Bivariate Distributions, Broderick O. Oluyede, Marvis Pararai Jan 2008

A Note On Extreme Bernoulli And Dependent Families Of Bivariate Distributions, Broderick O. Oluyede, Marvis Pararai

Mathematical Sciences: Faculty Publications

The objective and purpose of this note is to generate bivariate distributions via extreme Bernoulli distributions and obtain results on positively and negatively dependent families of bivariate binomial distributions generated by extreme Bernoulli distributions. Some distributional properties and results are presented. The factorial moment generating functions, correlation functions, conditional distributions and the regression functions are given.


A Partition Bijection Related To The Rogers-Selberg Identities And Gordon's Theorem, Andrew Sills Jan 2008

A Partition Bijection Related To The Rogers-Selberg Identities And Gordon's Theorem, Andrew Sills

Mathematical Sciences: Faculty Publications

We provide a bijective map from the partitions enumerated by the series side of the Rogers–Selberg mod 7 identities onto partitions associated with a special case of Basil Gordon's combinatorial generalization of the Rogers–Ramanujan identities. The implications of applying the same map to a special case of David Bressoud's even modulus analog of Gordon's theorem are also explored.


On The Ordinary And Signed Göllnitz-Gordon Partitions, Andrew Sills Jan 2008

On The Ordinary And Signed Göllnitz-Gordon Partitions, Andrew Sills

Mathematical Sciences: Faculty Publications

A partition of an integer n is a representation of n as an unordered sum of positive integers. In a recent paper [1], Andrews introduced the notion of a "signed partition," that is, a representation of a positive integer as an unordered sum of integers, some possibly negative.


Disturbing The Q-Dyson Conjecture, Andrew Sills Jan 2008

Disturbing The Q-Dyson Conjecture, Andrew Sills

Mathematical Sciences: Faculty Publications

I discuss the computational methods behind the formulation of some conjectures related to variants on Andrews’ q-Dyson conjecture.


Harmonic Analysis Related To Schrödinger Operators, Gestur Olafsson, Shijun Zheng Jan 2008

Harmonic Analysis Related To Schrödinger Operators, Gestur Olafsson, Shijun Zheng

Mathematical Sciences: Faculty Publications

In this article, we give an overview of some recent developments in Littlewood-Paley theory for Schrödinger operators. We extend the Littlewood-Paley theory for special potentials considered in our previous work [J. Fourier Anal. Appl. 12 (2006), no. 6, 653–674; MR2275390]. We elaborate our approach by considering a potential in C∞0 or the Schwartz class in one dimension. In particular, the low energy estimates are treated by establishing some new and refined asymptotics for the eigenfunctions and their Fourier transforms. We give a maximal function characterization of the Besov spaces and Triebel-Lizorkin spaces associated with H. Then we …


Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs Jan 2008

Ship Ballast Tanks: How Microbes Travel The World, Fred C. Dobbs

OES Faculty Publications

As the international shipping fleet travels the oceans, it carries with it hidden cargoes of microbes. Fred C. Dobbs explores the hazards posed and what can be done to counteract them.


Forcing And Dynamics Of Seafloor-Water Column Exchange On A Broad Continental Shelf, William B. Savidge, Ann Gargett, Richard A. Jahnke, James R. Nelson, Dana K. Savidge, R. Timothy Short, George Voulgaris Jan 2008

Forcing And Dynamics Of Seafloor-Water Column Exchange On A Broad Continental Shelf, William B. Savidge, Ann Gargett, Richard A. Jahnke, James R. Nelson, Dana K. Savidge, R. Timothy Short, George Voulgaris

OES Faculty Publications

Relict sediments of elevated permeability characterize the majority of continental shelves globally (Emery, 1968). In these settings, interactions between benthic boundary layer (BBL) flows and seabed topography generate pressure fluctuations that drive advective and dispersive porewater transport, dramatically increasing the magnitude and variability of porewater solute and particulate exchange across the sediment-water interface (Huettel et al., 1996; Huettel and Rusch, 2000). On broad shallow shelves with a relatively large area-to-volume ratio, the seafloor’s role is magnified. Energetic events may reorganize bedforms across a significant fraction of the shelf, leading to altered exchange dynamics that may persist long after the organizing …


Arctic Perennial Ice Cover Over The Last 14 Million Years, Dennis A. Darby Jan 2008

Arctic Perennial Ice Cover Over The Last 14 Million Years, Dennis A. Darby

OES Faculty Publications

Knowledge of the long-term history of the perennial ice is an important issue that has eluded study because the Cenozoic core material needed has been unavailable until the recent Arctic Coring Expedition (ACEX). Detrital Fe oxide mineral grains analyzed by microprobe from the last 14 Ma (164 m) of the ACEX composite core on the Lomonosov Ridge were matched to circum-Arctic sources with the same mineral and 12-element composition. These precise source determinations and estimates of drift rates were used to determine that these sand grains could not be rafted to the ACEX core site in less than a year. …


A Tribute To Peter George Brewer In Celebration Of His 65th Birthday, George T. F. Wong, Robert F. Anderson, Michael P. Bacon, Hein J. W. De Baar, James W. Murray, Mary I. Scranton Jan 2008

A Tribute To Peter George Brewer In Celebration Of His 65th Birthday, George T. F. Wong, Robert F. Anderson, Michael P. Bacon, Hein J. W. De Baar, James W. Murray, Mary I. Scranton

OES Faculty Publications

Peter George Brewer is an ocean chemist of the rare breed that can cross back and forth over the divide between being a front-line research scientist and being a research executive. As if that is not remarkable enough, in the process, he has also demonstrated sustained growth in the depth, breadth, and diversity of his scientific endeavors. Some of his formidable contributions to ocean chemistry have already been highlighted in a profile of him as a major mover and shaker in the field (Irion, 2001). Here, we provide additional glimpses of him from the perspective of a group of individuals …


Sublethal And Killing Effects Of Atmospheric-Pressure, Nonthermal Plasma On Eukaryotic Microalgae In Aqueous Media, Ying Zhong Tang, Xin Pei Lu, Mounir Laroussi, Fred C. Dobbs Jan 2008

Sublethal And Killing Effects Of Atmospheric-Pressure, Nonthermal Plasma On Eukaryotic Microalgae In Aqueous Media, Ying Zhong Tang, Xin Pei Lu, Mounir Laroussi, Fred C. Dobbs

OES Faculty Publications

In-depth studies on the interaction of nonthermal plasmas with microorganisms usually focus on bacteria; only little attention has been given to their effects on more complex eukaryotic cells. We report here nonthermal plasma's effects on cell motility, viability staining, and morphology of eukaryotic microalgae, with three marine dinoflagellates and a marine diatom as major targets. The effects on motility and viability staining depended on the time of exposure to plasma and the species of microalgae. We observed a strong pH decrease in aqueous samples (marine and freshwater algal cultures, their culture media, and deionized water) after exposure to plasma, and …


Maximizing Correlation In The Presence Of Missing Data, Xinfang Wang Jan 2008

Maximizing Correlation In The Presence Of Missing Data, Xinfang Wang

Logistics & Supply Chain Management: Faculty Publications

In this paper we address the problem of maximizing the correlation between two vectors of time series data, when one of the vectors has missing data and the timing of the missing data is unknown. The motivation for this work comes from environmental monitoring where because of monitoring malfunction, some data are lost. We study the use of integer programming and a genetic algorithm (GA) for this problem.


Schoolyard Improvements And Standardized Test Scores: An Ecological Analysis, Russ Lopez, Richard Campbell, James Jennings Jan 2008

Schoolyard Improvements And Standardized Test Scores: An Ecological Analysis, Russ Lopez, Richard Campbell, James Jennings

Gastón Institute Publications

Boston MA’s schoolyards had seriously deteriorated since the middle of the 20th century resulting in dangerous and unusable outdoor spaces. Beginning in the mid 1990s, a program to renovate these schoolyards has resulted in approximately half of the schools now having outdoor recreational, learning and garden spaces. This study compared the 4th grade test score results in renovated vs. unrenovated schools. Controlling for school demographics, schools that had a renovated schoolyard had more of their students passed the state mandated math test (1.06, 95% confidence interval = .00012, .12). Effects on the state mandated English language arts test were not …


Shallow Marine Carbonate Dissolution And Early Diagenesis-Implications From An Incubation Study, Xinping Hu, David J. Burdige Jan 2008

Shallow Marine Carbonate Dissolution And Early Diagenesis-Implications From An Incubation Study, Xinping Hu, David J. Burdige

OES Faculty Publications

Surface carbonate sediments fro, sites on the Bahamas Bank with different seagrass densities were incubated across a range of O2 delivery rates, to study the controls on metabolic carbonate dissolution in these sediments. The results continued the 1:1 ratio between the rates of O2 consumption and carbonate dissolution, demonstrating that microbial respiration was the rate-limiting step in metabolic carbonate dissolution. Furthermore, the dissolution we observed was actually net dissolution resulting front Coupled dissolution and reprecipitation. This carbonate reprecipitation occurs on the time scale of days, and significantly alters the pore water dissolved inorganic carbon (DIC) stable isotopic composition. …


Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins Jan 2008

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO2 levels. Rates of N2 and CO2 fixation and growth increased in step with increasing partial pressure of CO2 (pCO2), but only under Fe- replete conditions. N2) and carbon fixation rates at 75 Pa CO2 were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO2 …


Chemistry, Hiroki Sato Jan 2008

Chemistry, Hiroki Sato

Theses

Chemistry by Hiroki Sato, M.F.A Thesis, Rochester Institute of Technology, 2008 A description of the creation of a 3D computer animated film, "Chemistry," a project whose goal is to invoke an emotional response in the audience as they watch a reaction between a crystal and a light bulb in a laboratory. Includes thesis proposal, budget, timeline, original story boards, color stills, and a code for a Maya Python tool that helps to create and animate some complex geometrical objects.


Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett Jan 2008

Food Limitation In Larval Fish: Ontogenetic Variation In Feeding Scope And Its Potential Effect On Survival, Alexander B. Bochdansky, Peter Grønkjær, Pierre Pepin, William C. Leggett

OES Faculty Publications

We used the radiated shanny Ulvaria subbifurcataas a model species to explore the relative gut fullness from hatch to metamorphosis of wild larvae, and compared these values with those of laboratory-reared larvae fed at maximum rates. Ingestion rates of most wild larvae were above starvation levels but below the maximum feeding levels of laboratory-reared larvae. Twenty-six percent of freshly-hatched wild larvae and 11% of large, pre-settlement wild larvae had insufficient food in their stomach to satisfy metabolic requirements. These results, taken on their own, are consistent with the much hypothesized increased foraging performance and survival of larger larvae relative …


Faculty Senate Librarian's Report-2008, Georgia Southern University Jan 2008

Faculty Senate Librarian's Report-2008, Georgia Southern University

Faculty Senate: Librarian's Reports

No abstract provided.


Faculty Senate Minutes-2008 Jan 2008

Faculty Senate Minutes-2008

Faculty Senate Minutes

No abstract provided.


Honors @ Georgia Southern, University Honors Program Students And Staff, Georgia Southern University Jan 2008

Honors @ Georgia Southern, University Honors Program Students And Staff, Georgia Southern University

Honors College: News & Publications (2008-2020)

  • Nationally Competitive Scholarship Winners
  • Study abroad special
  • Alternative Spring Break: Honduras
  • Honors in Action
  • Alumni updates


Paper 3: Actively Engaging Pre-Service Teachers In Geometry And Measurement, Kadian M. Callahan Jan 2008

Paper 3: Actively Engaging Pre-Service Teachers In Geometry And Measurement, Kadian M. Callahan

Georgia Association of Mathematics Teacher Educators (GAMTE) Annual Conference (2007-2019)

Current work in mathematics education suggests that the learning experiences in which teachers engage during undergraduate study influences their knowledge of and beliefs about mathematics and the ways in which they will teach (Allen, et. al., 2008; CBMS, 2001; Hill, Rowan, & Ball, 2005; National Research Council, 2001). However, very little is known about pre-service teachers’ learning experiences and how those experiences influence their thinking about mathematics teaching and learning. The classroom excerpt described here attempts to illuminate how pre-service, elementary teachers’ active engagement in the learning of geometry and measurement influences their mathematical power: a positive disposition toward mathematics, …