Digital Commons Network^™

Apex Version 2.0: Latest Version Of The Cross-Platform Analysis Program For Exafs, Nicholas Dimakis, Grant Bunker

Physics & Astronomy Faculty Publications

This report describes recent progress on APEX, a free, open source, cross platform set of EXAFS data analysis software. In a previous report we described APEX 1.0 (Dimakis, N. and Bunker, G., 1999), a free and open source code suite of basic X-Ray Absorption Fine Structure (XAFS) data analysis programs for classical data reduction and single scattering analysis. The first version of APEX was the only cross platform (linux/irix/windows/MacOS) EXAFS analysis program to our knowledge, but it lacked important features like multiple scattering fitting, generic format conversion from ASCII to University of Washington (UW) binary-type files, and user friendly interactive …

Sales And Elections As Methods For Transferring Corporate Control, Ronald J. Gilson, Alan Schwartz

Faculty Scholarship

Delaware case law has rendered the tender offer obsolete as a method for purchasing a company whose directors oppose the acquisition. A potential acquirer facing target opposition today must run an insurgent director slate, in the expectation that its directors are more likely to sell. The Delaware courts have not justified their preference for elections over markets as the preferred vehicle for implementing changes in control. Informal scholarly analyses ask transaction cost questions, such as whether proxy contests are more costly than takeovers. This article attempts to break new ground by asking whether there are systematic differences in the performance …

Group Learning In Technical Courses, Donald E. Smith

Journal of Aviation/Aerospace Education & Research

It is one thing to utilize group learning techniques in non-technical courses in which a group discussion on the meaning of a literary passage or the effects of an economic or political decision could take advantage of a group dynamic and all that group participation has to offer. It is quite another when the subject material is purely technical and relatively unyielding as in math or physics based courses.

A Comparison Of The Learning Styles Of Aviation And Non-Aviation College Students, Tim Brady, Alan Stolzer, Bradley Muller, Debbie Schaum

Journal of Aviation/Aerospace Education & Research

In contrast to established educational fields such as mathematics, the discipline of aviation education is relatively young. Despite strong signs that our discipline is maturing (Brady 1991), it is not clear as to the extent to which a larger body of instructional theory can be applied specifically to aviation instruction (Telfer 1993, p. 210) or the broader field of aviation education. A starting point in unraveling this complex question is to better understand the characteristics of aviation students. In recent years a limited number of researchers have begun to address this and related questions (Moore and Telfer 1990; Quilty 1996; …

Yield Management, Carlos Alberto Castro Pena

Journal of Aviation/Aerospace Education & Research

Historically, airlines have operated in a tightly regulated environment. This environment has been regulated by governments and self-regulated through organizations such as the International Air Transport Association (IATA) The early airline policy for the fare activities was based on offering all the seats on the airplane (or in the coach of the airplane) at the same rate. When the industry entered the 1960s with bigger and faster planes, new types of fares were being approved by the Civil Aeronautical Board (CAB) on certain routes, including lower-night coach fares, and tour-basing fares. There were no capacity controls on these fares. All …

Reasoning With Rules, Joseph Raz

Faculty Scholarship

What is special about legal reasoning? In what way is it distinctive? How does it differ from reasoning in medicine, or engineering, physics, or everyday life? The answers range from the very ambitious to the modest. The ambitious claim that there is a special and distinctive legal logic, or legal ways of reasoning, modes of reasoning which set the law apart from all other disciplines. Opposing them are the modest, who claim that there is nothing special to legal reasoning, that reason is the same in all domains. According to them, only the contents of the law differentiate it from …

Photocuring Of Acrylate Oligomers In The Presence Of Vinyl Phosphonic Acids As A Flame Retarding Monomer And The Properties Of The Cured Films, Tüli̇n İmamoğlu, Yusuf Yağci

Turkish Journal of Chemistry

Photocuring of formulations containing polyurethane based acrylates and a flame retarding monomer (FR), namely vinyl phosphonic acid with an \alpha -cleavage type photoinitiator; 2-hydroxy-2-methylphenyl propane-1-one were studied. The flame retardancy, and the physical and mechanical properties of the cured films were determined.

Determination Of Hydrochlorothiazide And Enalapril Maleate In Tablet Formulations By Reversed-Phase Hplc, Idrees F. Al-Momani̇

Turkish Journal of Chemistry

A high-performance liquid chromatographic procedure is presented for the determination of hydrochlorothiazide (HCT) and enalapril maleate (EM) in pharmaceutical tablets. An aliquot of the sample is dissolved in 15% acetonitrile (ACN) containing thiophylline as an internal standard and chromatographed on a Supelcosil LC-8 (5 \mu m), (150 mm x 4.6 mm i.d.) column. The mobile phase was 3.0 mM tetrabutylammoniumhydrogen sulfate (TBAHS) in ACN/water/triethylamine (TEA), (14, 85.6, 6.4 V/V) adjusted to pH 4.1 by glacial acetic acid. The detection was at 220 nm. The method was tested for linearity, accuracy, recovery, and specificity.

Voltammetric And Polarographic Studies Of Eriochrome Black T - Nickel(Ii) Complex, Osman Çakir, Emi̇ne Ertürk Coşkun, Ender Bi̇çer, Semi̇ha Çakir

Turkish Journal of Chemistry

The electrochemical behaviour of complexes of Eriochrome Black T (EBT) with Ni(II) was studied. It was observed that EBT forms 1:1 and 1:2 complexes with Ni(II) in 0.1 M phosphate buffer at pH 6.0 by using Square-wave voltammetry (SWV), Cyclic voltammetry (CV), Direct Current Polarography (Sampled DCP) and Controlled Potential Coulometry (CPC). It was found that the reduction processes of Ni(II)-EBT complexes are irreversible. The stability constants of the Ni(II)-EBT complexes were evaluated with the DeFord-Hume procedure at different ligand concentrations using SWV. The logarithm values of stability constants of 1:1 and 1:2 Ni(II)-EBT complexes are 8.17 and 11.17, respectively.

Fluorimetric Detection Of Insulin In The Presence Of Eu(Iii) - {Pyridine - 2,6 - Dicarboxylate} Tris Complex, Elmas Gök, Serdar Ateş

Turkish Journal of Chemistry

Bovine insulin solutions (pH=9.3) have maximum absorption at 278 \pm 2 nm and an intrinsic emission at 305 nm when excited at 282 nm. The relative fluorescence intensities show linear dependence on its concentration: 10 \mug/mL< [Ins] < 200 \mug/mL. When Eu(PDA)_{3}^{3-} tris complex is added to these solutions, it has a hyperchromic effect at 278 nm absorption band of insulin, sensitizing the emission intensities of central Eu^{3+} metal ion of the complex at 590 and 615 nm, and simultaneously quenching the emission intensity of hormone at 305 nm. Stern-Volmer plots show that a mechanism of bimolecular quenching at 305 nm and sensitization at 615 nm are valid up to a mole ratio, R = [Eu(PDA)_{3}^{3-}]/[Ins] < 2.0. An intramolecular rather than an intermolecular energy transfer is proposed. An apparent binding constant, log K_{app}=4.70 \pm 0.13, is calculated for Ins-[Eu(PDA)_{3}^{3-}]_{2} type product, the presence of which may offer a new luminescence technique as a diagnostic tool and an alternative to radio-iodinated (^{131}I -) insulin. A simple, rapid and accurate quantitation of insulin is proposed by using a fixed concentration of Eu(PDA)_{3}^{3-}, and measuring its initial F_{0} at \lambda_{exc}/ \lambda_{em}=282/615 nm and the difference, \DeltaF after sensitization when \sim 100 microliters of insulin sample is added. The coefficient of variation (CV), the relative error and minimum detectable amount of bovine insulin hormone are found to be 3.0%, 1.2% and 7.3 \pm 0.2 \mug /mL respectively.

Evidence For A Hybrid Ping Pong-Semirandom Mechanism For Human Jejunal Glutathione Disulfide Reductase, Nazmi̇ Özer, İzzet Hamdi̇ Öğüş

Turkish Journal of Chemistry

Initial rate versus substrate concentration, [S], profiles (at pH 7.4, 37^oC) for human jejunal glutathione disulfide reductase indicated partial substrate inhibition by GSSG at fixed [NADPH] \le 40 \mu M. Saturation by NADPH assumed an increasingly sigmoidal character at fixed [GSSG] \ge 20 \mu M. The results were interpreted in terms of a hybrid ping pong-semirandom mechanism proceeding through both E.NADPH (ping pong pathway) and E.GSSG (ordered pathway) complexes. When V(apparent) versus [GSSG] and [NADPH] were plotted, hyperbolic curves were obtained. Plotting 1/Vm(apparent) versus 1/[NADPH] and 1/[GSSG] yielded two lines with different slopes but intersecting at the same point on …

Synthesis And Structure Of Systems Containing Pyramidalized And Strained Double Bond: An Investigation On The Cycloaddition Reactions Of Cis- And Trans-3,8-Dicarbomethoxy-3,8-Dihydroheptalene, Nurullah Saraçoğlu, Abdullah Menzek, Meti̇n Balci

Turkish Journal of Chemistry

The cycloaddition reactions of cis-3,8-dicarbomethoxy-3,8-dihydroheptalene cis-2 and trans-3,8-dicarbomethoxy-3,8-dihydroheptalene trans-2 with various dienophiles such as dimethyl acetylenedicarboxylate (DMAD), p-benzoquinone, maleic anhydride, tetracyanoethylene, naphtoquinone gave monoaddition products 15-23. Further addition of benzyne and dimethyl acetylenedicarboxylate to 18 resulted in the formation of the compounds syn-25 and syn-26 having pyramidalized double bonds. The addition of benzyne to 21 and the addition of dimethyl acetylenedicarboxylate to 21, 22 and 23 gave the anti configuration products anti-26, 27 and 28, respectively. X-ray structures of syn-25, syn-26 and anti-26 show the pyramidalized angles to be 16.5^o, 19.9^o and 8.0^o, respectively.

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

Simultaneous Determination Of Inorganic Anions And Organic Acids By Capillary Electrophoresis, Nevi̇n Özteki̇n, F. Bedi̇a Eri̇m Berker

Turkish Journal of Chemistry

A rapid, easy, and reproducible method for the simultaneous determination of inorganic anions and organic acids is reported. The method is based on the separation of anions in a capillary coated with a cationic polymer, polyethyleneimine (PEI). Four inorganic anions (chloride, sulfate, iodate and phosphate) and eight organic acids (oxalate, tartarate, malate, succinate, citrate, acetate, lactate, and propionate) were separated and quantified within 7 min by using 2,6-pyridinedicarboxylic acid (PDC) as the background electrolyte. The minimum detection limits are 0.67-2.87 \mu g/mL for inorganic ions and 0.38-2.84 \mu g/mL for organic acids. Reproducibilities in migration times (RSD%) for both inorganic …

Adsorption Of Some Textile Dyes By Hexadecyltrimethylammonium Bentonite, Özlem Ceyhan, Demet Baybaş

Turkish Journal of Chemistry

In this study, hexadecyltrimethylammonium (HDTMA) bentonite was synthesized by placing alkylammonium cation onto bentonite. Adsorption of some textile dyes such as Everdirect Supra Yellow PG, Everdirect Supra Orange 26 CG, Everdirect Supra Rubine BL, Everdirect Supra Blue 4BL and Everdirect Supra Red BWS on Na-bentonite and HDTMA-bentonite was investigated. While the Na-bentonite had no affinity for the dyes, the HDTMA-bentonite showed significant adsorption from aqueous solution. The Langmuir and Dubinin-Rasdushkevich (D-R) isotherm equations were applied to the data and values of parameters of these isotherm equations were evaluated. The mean energy of adsorption, E, was also calculated from the adsorption …

Structural Studies Of Water-Soluble \Beta-Brominated Manganese Porphyrins: Stabilities Of Mntdcsppbr _{8} And Mntsppbr _{8} As Homogeneous And Supported Reagents Toward Hydrogen Peroxide And Sodium Hypochlorite, Hayretti̇n Türk, Hüseyi̇n Berber

Turkish Journal of Chemistry

This article describes the structural stabilities of [2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(2,6-dichloro-3-sulfonatophenyl)porphinato]manganese(III) X (where X = H_{2}O and/or OH^{-} , depending on pH) (MnTDCSPPBr_{8} ) and [2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetra(4-sulfonatophenyl)porphinato] manganese(III) X (where X = H_{2}O and/or OH^{-} , depending on pH) (MnTSPPBr_{8} ) toward H_{2}O_{2} and NaOCl at various pH's, I = 0.2 M and 30^oC. In addition, the structural stabilities of these manganese porphyrins were investigated when they were bound to quaternary ammonium containing supports, namely, hexadecyltrimethylammonium bromide (CTAB), 2,6-ionene, 2,10-ionene and a poly[(vinylbenzyl)trimethylammonium chloride] latex. In alkaline media, both manganese porphyrins degraded and precipitated even in the absence of both of the oxidants. In …

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

On Stochastic Comparisons Of Energy Functions With Applications, Broderick O. Oluyede

Mathematical Sciences: Faculty Publications

We develop simple methods for the stochastic comparisons of informational energy functions. We introduce modified informational energy functions and uncertainty of parameter functions are introduced for models with realistic parameter spaces. We present inequalities, comparisons, and applications including test procedures for testing the equality of informational energy functions. Some illustrative examples are also presented.

On Moment Inequalities And Stochastic Ordering For Weighted Reliability Measures, Broderick O. Oluyede, Mekki Terbeche

Mathematical Sciences: Faculty Publications

We obtain stochastic inequalities, error bounds, and classification probability for a general class of distributions. We introduce the notion of variability ordering via the probability functional and comparisons made for the weighted and the original distributions. We present moment inequalities, comparisons, and applications.

Towards The Asymmetric Synthesis Of Ascochlorin, Özdemi̇r Doğan, Wolfgang Oppolzer

Turkish Journal of Chemistry

A synthetic approach is described to the asymmetric synthesis of ascochlorin (1), an antiviral antibiotic, based on the construction of a sesquiterpene unit via asymmetric Diels-Alder reaction of tigloyl sultam 4 & butadiene, and the introduction of the aromatic side chain (C9-C12 unit) by employing cuprate chemistry.

Purification And Partial Characterisation Of Superoxide Dismutase From Chicken Erythrocytes, Tüli̇n Aydemi̇r, Leman Tarhan

Turkish Journal of Chemistry

Superoxide dismutase (SOD), which plays a very important role in protecting organisms from oxygen toxicity, was purified from chicken erythrocyte and partially characterised. Erythrocyte membranes were disintegrated via freeze-thaw methods in the presence of Triton X-100. Following ethanol precipitation, SOD-containing solution was applied to DEAE-cellulose and then Sephadex G-100 gel columns. Chicken erythrocyte SOD was purified 508-fold with a specific activity of 8,480 units per mg. The molecular weight was estimated to be 30.6 kDa \pm 0.4 by gel filtration. The enzyme was composed of two subunits of equal size and contained one atom of copper and one atom of …

Characterization Of Lipids And Fatty Acid Methyl Ester Contents In Leaves And Roots Of Crocus Vallicola, Nuretti̇n Yayli, Zerri̇n Kiran, Hasan Seymen, Hasan Genç, Mustafa Küçüki̇slamoğlu

Turkish Journal of Chemistry

The chemical composition of the fatty acids methyl esters (FAMEs) and other lipids in leaves and roots of Crocusvallicola were analyzed by gas chromatography-mass spectrometry(GC-MS). In this work, twenty-eight compounds, including 22 FAMEs, 1 aldehyde, 3 hydrocarbons (substitute alkane and alkene), 2 alcohols in the leaves and twenty-one compounds (17 FAMEs, 1 anhydride, 1 substitute alcohol, 1 ketone, 1 substitute amide) in the roots were identified by GC-MS from C. vallicola. The FAMEs in leaves and roots were highly similar; only the amounts of the esters were different. Key Words: Crocus vallicola, leaves, roots, FAMEs

Spectrophotometric Determination Of Propranolol As Cu(Ii), Ni(Ii) And Co(Ii) Dithiocarbamate Complexes, Ayşegül Gölcü, Mustafa Dolaz, Selahatti̇n Seri̇n

Turkish Journal of Chemistry

A spectrophotometric method was developed for the determination of the beta adrenergic blocking drug propranolol. The method was based on the formation of Cu(II), Ni(II) and Co(II)-dithiocarbamate complexes from the secondary amine group of propranolol with carbondisulfide (CS_{2}) and the acetate salts of the metals in ammonia medium. The method was applied to the analysis of propranolol tablets and the results were statistically compared with those obtained by the official method using t- and F-tests. There was no significant difference between the mean values and the precisions of the two methods at the 95% confidence level.

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

An Analysis Of A Radio Frequency Sensor As A Means To Remotely Sense Selected Surface Topographies In An Agriculture Environment, Barry Michael Alexia

Dissertations and Theses @ UNI

Remote sensing is the science and art of obtaining information about an object, area or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation. The remotely sensed data can be of many forms, including variations in force distribution, acoustic wave distribution, or electromagnetic energy distribution.Information thus acquired can be used for observing,monitoring, and studying planetary surfaces and environments.

Because there are many ways to acquire data about targets of interest, there are many types of remote sensors that can be used, including visible, infrared, and active …

Seasonal Climatology Of Hydrographic Conditions In The Upwelling Region Off Northern Chile, J. L. Blanco, A. C. Thomas, M.-E. Carr, P. T. Strub

OES Faculty Publications

Over 30 years of hydrographic data from the northern Chile (18°S-24°S) upwelling region are used to calculate the surface and subsurface seasonal climatology extending 400 km offshore. The data are interpolated to a grid with sufficient spatial resolution to preserve crossshelf gradients and then presented as means within four seasons: austral winter (JulySeptember), spring (October-December), summer (January-March), and fall (April-June). Climatological monthly wind forcing, surface temperature, and sea level from three coastal stations indicate equatorward (upwelling favorable) winds throughout the year, weakest in the north. Seasonal maximum alongshore wind stress is in late spring and summer (DecemberMarch). Major water masses …

Hydrogeological Characterization Of The South Oyster Bacterial Transport Site Using Geophysical Data, Susan S. Hubbard, Jinsong Chen, John Peterson, Ernest L. Majer, Kenneth H. Williams, Donald J. Swift, Brian Mailloux, Yoram Rubin

OES Faculty Publications

A multidisciplinary research team has conducted a field-scale bacterial transport study within an uncontaminated sandy Pleistocene aquifer near Oyster, Virginia. The overall goal of the project was to evaluate the importance of heterogeneities in controlling the field-scale transport of bacteria that are injected into the ground for remediation purposes. Geochemical, hydrological, geological, and geophysical data were collected to characterize the site prior to conducting chemical and bacterial injection experiments. In this paper we focus on results of a hydrogeological characterization effort using geophysical data collected across a range of spatial scales. The geophysical data employed include surface ground-penetrating radar, radar …

Field Methodology For The Determination Of The Prevalence Of Giardia Cysts And Cryptosporidium Oocysts Drinking Water And Its Association To The Development Of Diarrheal Disease In The Transylvania Region Of Romania, Rick J. Bauer

Dissertations and Theses @ UNI

The purpose of this study was to analyze the drinking water of 69 individuals living in the Transylvania region of Romania for the presence of Giardia cysts and Cryptosporidium oocysts. The ultimate objective was to determine if a correlation exists between the presence and concentrations of these two protozoa and the reported frequency and average severity of diarrheal disease in the study group members.

To accomplish this goal, a collection, emulsion, concentration, labeling, and identification method had to be developed that could operate effectively in an international field setting. The protocol selected included the collection of samples using a compressed …

Growth Rate Variability And Lipofuscin Accumulation Rates In The Blue Crab Callinectes Sapidus, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OES Faculty Publications

To better understand growth and age-pigment (lipofuscin) accumulation rates of the blue crab Callinectes sapidus under natural conditions, juveniles (33 to 94 mm carapace width) were reared in outdoor ponds for over 1 yr. Growth rates, measured by carapace width, during summer and fall exceeded all those reported in the literature; the initial carapace width of 59 ± 14 mm (mean ± SD) increased to 164 ± 15 mm within a 3 mo period. No growth occurred during winter months (November to April) at low water temperatures. Growth rates of crabs in ponds were substantially higher (von Bertalanffy growth parameter …

The Effect Of Spectral Composition On The Photochemical Production Of Hydrogen Peroxide In Lake Water, Andrea Y. L. Wong, George T. F. Wong

OES Faculty Publications

Hydrogen peroxide was produced when samples of lake water were exposed to direct or filtered sunlight in which UV or UV(B+C) light was selectively removed. In all cases, the concentration of hydrogen peroxide increased linearly with time-integrated irradiance. While both visible and UV light can induce the formation of hydrogen peroxide, the contribution from the latter was disproportionately large as it was responsible for about two-thirds of the formation of hydrogen peroxide. Among the UV lights, the contributions from UV-A and UV-(B+C) light were 70% and 30% respectively. The contribution from UV-A light was equivalent to about one half of …