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2009

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Articles 6721 - 6750 of 7616

Full-Text Articles in Physical Sciences and Mathematics

Effect Of The Regiochemistry Of Butyl Amide Substituents On The Solution-State Structures Of Lanthanide(Iii) Dota-Tetraamide Complexes, Tomoyasu Mani, Gyula Tircsó, Piyu Zhao, A. Dean Sherry, Mark Woods Jan 2009

Effect Of The Regiochemistry Of Butyl Amide Substituents On The Solution-State Structures Of Lanthanide(Iii) Dota-Tetraamide Complexes, Tomoyasu Mani, Gyula Tircsó, Piyu Zhao, A. Dean Sherry, Mark Woods

Chemistry Faculty Publications and Presentations

The coordination geometry adopted by the lanthanide complexes of DOTA-tetraamides is a critical factor in determining their water exchange kinetics. Controlling the water exchange kinetics of DOTA-tetraamide complexes, and by extension their coordination geometry, is of particular interest because of the potential application of this class of complex as PARACEST MRI contrast agents. To facilitate the maximum CEST effect at the lowest pre-saturation powers much slower exchange kinetics are required than are commonly observed with these types of chelates. Complexes that adopt the more slowly exchanging square antiprismatic coordination geometry are therefore preferred; however, the factors that govern which coordination …

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Three-Dimensional Spatial Information Systems: State Of The Art Review, Bianca Schoen-Phelan, D. Laefer, S. W. Morrish, M. Bertolotto Jan 2009

Three-Dimensional Spatial Information Systems: State Of The Art Review, Bianca Schoen-Phelan, D. Laefer, S. W. Morrish, M. Bertolotto

Articles

A spatial information system (SIS) is critical to the hosting, querying, and analyzing of spatial data sets. The increasing availability of three-dimensional (3D) data (e.g. from aerial and terrestrial laser scanning) and the desire to use such data in large geo-spatial platforms have been dual drivers in the evolution of integrated SISs. Within this context, recent patents demonstrate efforts to handle large data sets, especially complex point clouds. While the development of feature-rich geo-systems has been well documented, the implementation of support for 3D capabilities is only now being addressed. This paper documents the underlying technologies implemented for the support …

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Scattering From A Tenuous Random Medium With Applications In Optics, Jonathan Blackledge Jan 2009

Scattering From A Tenuous Random Medium With Applications In Optics, Jonathan Blackledge

Articles

Mathematical models for the scattering of light (and other radiation) tend to fall into two categories based on a weak field condition (single scattering processes) or a strong field condition (multiple scattering processes). In the latter case, the complexity of deterministic models coupled with available solutions often fail to provide results that are of value to engineering systems (e.g. imaging systems). For this reason, multiple scattering problems are often approached using stochastic modelling methods whose foundations lie in random walk theory where the amplitude and phase of the scattered field are taken to conform to an appropriate statistical process and …

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Insulation Condition Assessment Of Power Transformers Using Accelerated Ageing Tests, Mohammad Mirzaie, Ahmad Gholami, Hamid Reza Tayebi Jan 2009

Insulation Condition Assessment Of Power Transformers Using Accelerated Ageing Tests, Mohammad Mirzaie, Ahmad Gholami, Hamid Reza Tayebi

Turkish Journal of Electrical Engineering and Computer Sciences

Thermal stress due to losses and environment temperature causes degradation to paper/oil insulation systems in transformers, even at operating temperature. Experience indicates that thermal ageing of oil and paper in power transformers leads to the change of some insulation characteristics. In this paper, insulating papers immersed in oil have been acceleratory aged at 140, 150, and 160 °C under laboratory conditions. Some of the oil properties, such as water content, breakdown voltage, acidity, together with the aged insulating paper properties such as electric strength, dielectric dissipation factor and tensile strength were measured and analyzed. Also, insulation system conditions under thermal …

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Voltage Control Of Self-Excited Induction Generator Using Genetic Algorithm, Dheeraj Joshi, Kanwarjit Singh Sandhu, Mahender Kumar Soni Jan 2009

Voltage Control Of Self-Excited Induction Generator Using Genetic Algorithm, Dheeraj Joshi, Kanwarjit Singh Sandhu, Mahender Kumar Soni

Turkish Journal of Electrical Engineering and Computer Sciences

Self-excited induction generators (SEIG) are found to be most suitable candidate for wind energy conversion application required at remote windy locations. Such generators are not able to maintain the terminal voltage with load as, a literature survey reveals, the voltage profile falls sharply with load. In this paper an attempt has been made to improve the voltage profile of a self-excited induction generator. A new methodology based upon Genetic Algorithm (GA) is proposed to compute the steady state performance of the model including core loss branch. Further efforts are made to control the terminal voltage under loaded conditions. Simulated results …

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Variance And Kurtosis-Based Characterization Of Resonances In Stochastic Transmission Lines: Local Versus Global Random Geometries, Ousmane Sy, Martijn Van Beurden, Bastiaan Michielsen, Antonius Tijhuis Jan 2009

Variance And Kurtosis-Based Characterization Of Resonances In Stochastic Transmission Lines: Local Versus Global Random Geometries, Ousmane Sy, Martijn Van Beurden, Bastiaan Michielsen, Antonius Tijhuis

Turkish Journal of Electrical Engineering and Computer Sciences

A stochastic method is proposed to characterize electromagnetic couplings involving geometrically perturbed transmission lines. A combined exploitation of suitably defined statistical tools is presented to appreciate the intensity of the dispersion of response variables both physically via the variance, and statistically through the kurtosis or fourth-order moment. The usefulness of this method to analyze resonances is illustrated by the study of a transmission line affected by two different types of random geometrical perturbations, viz. a local deformation modeled by a wavelet and global sinusoidal undulations.

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Electronic Differential With Direct Torque Fuzzy Control For Vehicle Propulsion System, Kada Hartani, Mohamed Bourahla, Yahia Miloud, Mohamed Sekour Jan 2009

Electronic Differential With Direct Torque Fuzzy Control For Vehicle Propulsion System, Kada Hartani, Mohamed Bourahla, Yahia Miloud, Mohamed Sekour

Turkish Journal of Electrical Engineering and Computer Sciences

We model an electronic differential that will offer the best vehicle stability on a curved road. The proposed traction system consists of two permanent magnet synchronous (PMS) machines that ensure the drive of two back-driving wheels. The contribution of each wheel to the advance of the vehicle is represented by an element conveying the accumulation of mechanical coupling. The proposed control structure is based on the direct torque fuzzy control for each wheel-motor. Different simulations have been carried out: vehicle driven ons straight road, vehicle driven on straight road with slope, and vehicle driven over a road curved left and …

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Conductive Emi Noise Measurement For Switched Reluctance Drive, Hao Chen, Xiaohui Qiu, Yang Zhao Jan 2009

Conductive Emi Noise Measurement For Switched Reluctance Drive, Hao Chen, Xiaohui Qiu, Yang Zhao

Turkish Journal of Electrical Engineering and Computer Sciences

The component parts of the tested four-phase Switched Reluctance drive are described with the four-phase 8/6 structure double salient reluctance motor, the four-phase asymmetric bridge power converter and the 89C52 MCU digital controller. The conductive electromagnetic interference noise measurement equipment is described with the function of separated common-mode noise and differential-mode noise. The tested results of common-mode noise and differential-mode noise of the tested Switched Reluctance drive are presented and the tested results of frequency spectrum are given.

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Converging Flow Between Coaxial Cones, O. Hall, A. D. Gilbert, C. P. Hills Jan 2009

Converging Flow Between Coaxial Cones, O. Hall, A. D. Gilbert, C. P. Hills

Articles

Fluid flow governed by the Navier-Stokes equation is considered in a domain bounded by two cones with the same axis. In the first, 'non-parallel' case, the two cones have the same apex and different angles θ = α and β in spherical polar coordinates (r, θ, φ). In the second, 'parallel' case, the two cones have the same opening angle α, parallel walls separated by a gap h and apices separated by a distance h/sinα. Flows are driven by a source Q at the origin, the apex of the lower cone in the parallel case. The Stokes solution for the …

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Equations Of The Camassa-Holm Hierarchy, Rossen Ivanov Jan 2009

Equations Of The Camassa-Holm Hierarchy, Rossen Ivanov

Articles

The squared eigenfunctions of the spectral problem associated with the CamassaHolm (CH) equation represent a complete basis of functions, which helps to describe the inverse scattering transform for the CH hierarchy as a generalized Fourier transform (GFT). All the fundamental properties of the CH equation, such as the integrals of motion, the description of the equations of the whole hierarchy, and their Hamiltonian structures, can be naturally expressed using the completeness relation and the recursion operator, whose eigenfunctions are the squared solutions. Using the GFT, we explicitly describe some members of the CH hierarchy, including integrable deformations for the CH …

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Multicast Encryption Infrastructure For Security In Sensor Networks, Richard R. Brooks, Brijesh Pillai, Matthew Pirretti, Michele C. Weigle Jan 2009

Multicast Encryption Infrastructure For Security In Sensor Networks, Richard R. Brooks, Brijesh Pillai, Matthew Pirretti, Michele C. Weigle

Computer Science Faculty Publications

Designing secure sensor networks is difficult. We propose an approach that uses multicast communications and requires fewer encryptions than pairwise communications. The network is partitioned into multicast regions; each region is managed by a sensor node chosen to act as a keyserver. The keyservers solicit nodes in their neighborhood to join the local multicast tree. The keyserver generates a binary tree of keys to maintain communication within the multicast region using a shared key. Our approach supports a distributed key agreement protocol that identifies the compromised keys and supports membership changes with minimum system overhead. We evaluate the overhead of …

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Life History Parameters Of The Humpback Whale (Megaptera Novaengliae) In The Waters Of The Gulf Of Maine For The 2007 Feeding Season, Meghan Wert Jan 2009

Life History Parameters Of The Humpback Whale (Megaptera Novaengliae) In The Waters Of The Gulf Of Maine For The 2007 Feeding Season, Meghan Wert

Undergraduate Review

The humpback whale (Megaptera novaengliae) is an endangered species of baleen whale that feeds in the waters of the Gulf of Maine during the spring, summer and fall. The worldwide population of humpback whales ranges from 60,000 to 80,000 individuals and the population within the Gulf of Maine is estimated between 9,000 to 11,000. Humpback whales are a large baleen whale that reaches an average length of 40 to 50 feet and a weight of 35 to 40 tons. Although protected worldwide since the International Whaling Commission in 1964, this population has increased slowly and is still considered …

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Singing The Moly Blues: The Direct Use Of Molybdenum Clusters As A Precursor To The Development Of Molybdenum Blue Glazes, Margaret Fiedler Jan 2009

Singing The Moly Blues: The Direct Use Of Molybdenum Clusters As A Precursor To The Development Of Molybdenum Blue Glazes, Margaret Fiedler

Undergraduate Review

Cobalt is currently the most commonly used blue colorant for ceramic glazes, however due to its toxicity in powder form there is a need for an alternative. Molybdenum, more specifically molybdenum oxide, is one alternative that has shown promise. This research is aimed at the direct incorporation of reduced molybdenum clusters into the glaze matrix. Two compounds have been synthesized that exhibit an intense blue color, Na15[MoVI126MoV28O457H14(H2O)70]0.5-[MoVI124MoV28O427H14(H2O)68]0.5 …

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An Optical Scalar Approach To Weak Gravitation Lensing, Louis Bianchini Jan 2009

An Optical Scalar Approach To Weak Gravitation Lensing, Louis Bianchini

Undergraduate Review

We assume a thick gravitational lens governed by a Baltz n=1 matter density model. From the gravitational potential we then derive expressions for a Weyl tensor component and Ricci tensor component. A perturbative approach is taken to solve for the convergence and shear as given by Sach’s equation. By applying the geodesic deviation equation to a bundle of light rays with our expressions for the optical scalars we are able to derive expressions for the image shape and size at any point along the path from source to observer, in the case of an axially symmetric lens and source.

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Modeling Weak Gravitational Lensing Through C++, Christopher Cepero Jan 2009

Modeling Weak Gravitational Lensing Through C++, Christopher Cepero

Undergraduate Review

Gravitational Lensing has become an integral part of astrophysics and the study of matter in the universe. In weak gravitational lensing, an object appears distorted when viewed from the observer’s perspective. This is caused by the bundle of light being distorted by an object of considerable mass. Because the distance to each part of this bundle is not the same, the rays of light are affected differently causing a shearing and magnification of the image. This alteration in the image we see can be modeled using the thin lens approximation. By integrating the equations for light travel based on general …

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Pioneering The Personal Robotics Industry, Russell Nickerson Jan 2009

Pioneering The Personal Robotics Industry, Russell Nickerson

Undergraduate Review

The up and coming industry that I will be reporting about here is the personal and home robotics industry. I will show how the development cycle in the United States functions. I will then answer the question: What are the main limits that hold back this industry? The U.S. approach to robotics will be contrasted with Japan’s approach as Japan has another very well developed robotics program.

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Dynamic Adaptation Of Joint Transmission Power And Contention Window In Vanet, Danda B. Rawat, Gongjun Yan, Dimitrie C. Popescu, Michele C. Weigle, Stephan Olariu Jan 2009

Dynamic Adaptation Of Joint Transmission Power And Contention Window In Vanet, Danda B. Rawat, Gongjun Yan, Dimitrie C. Popescu, Michele C. Weigle, Stephan Olariu

Electrical & Computer Engineering Faculty Publications

In this paper, we propose an algorithm for joint adaptation of transmission power and contention window to improve the performance of vehicular network in a cross layer approach. The high mobility of vehicles in vehicular communication results in the change in topology of the Vehicular Ad-hoc Network (VANET) dynamically, and the communication link between two vehicles might remain active only for short duration of time. In order for VANET to make a connection for long time and to mitigate adverse effects due to high and fixed transmission power, the proposed algorithm adapts transmission power dynamically based on estimated local traffic …

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6-Ketomethyl Phenanthridine As A New Carrier In The Construction Of A Highly Selective Fe(Iii) Ion-Selective Membrane Electrode, R. Maleki, Reza Hosseinzadeh, Hossein Mehrabi, Ali Hassanzadeh, Khalil Farhadi Jan 2009

6-Ketomethyl Phenanthridine As A New Carrier In The Construction Of A Highly Selective Fe(Iii) Ion-Selective Membrane Electrode, R. Maleki, Reza Hosseinzadeh, Hossein Mehrabi, Ali Hassanzadeh, Khalil Farhadi

Turkish Journal of Chemistry

A new Fe^{3+} ion-selective membrane electrode based on 6-ketomethyl phenanthridine (6-KMPT) and 1-(4-dimethyl aminophenyl)-2-(5H-phenanthridine-6-ylidene)-ethanone, which were incorporated in a plasticized polyvinyl chloride (PVC) membrane, is described. The optimized membrane demonstrated a linear dynamic range of 5.2 \times 10^{-6}-1.0 \times 10^{-2} M, with a near Nernstian slope of 19.5 \pm 1.5 mV per decade and a detection limit of 1.2 \times 10^{-6} M. The electrode showed high selectivity for Fe^{3+} ions in comparison to other metal ions. The effect of membrane composition on the potential response of the electrode was studied. The best performance was observed for the membrane comprised of …

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On The Structure Sensitivity Of Co Oxidation On Alumina Supported Pd--Pt Bimetallic Catalysts, Sarp Kaya, Ebru Erunal, Riad Shaltaf, Şi̇nasi̇ Elli̇altioğlu, Deni̇z Üner Jan 2009

On The Structure Sensitivity Of Co Oxidation On Alumina Supported Pd--Pt Bimetallic Catalysts, Sarp Kaya, Ebru Erunal, Riad Shaltaf, Şi̇nasi̇ Elli̇altioğlu, Deni̇z Üner

Turkish Journal of Chemistry

CO oxidation reaction was studied over monometallic and bimetallic palladium--platinum catalysts at 25:75, 50:50, and 75:25 Pd:Pt atomic fractions co-impregnated over a \gamma -Al_2O_3 support. The size of the metal particles, measured by modified hydrogen chemisorption, increased as the Pd fractions in the catalyst increased. The surface compositions and site metal distributions of the catalysts determined from Monte Carlo simulations indicated that Pd atoms segregated to the surface: at low Pd levels, Pd occupied preferentially 6 and 7 coordinated defect-like sites. As the Pd fraction increased, first 8 coordinated (100) and then 9 coordinated (111) planes were populated. At low …

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A Facile Method For The Preparation Of Poly(4-Vinylpyridine) Nanoparticles And Their Characterization, Nurettin Sahiner Jan 2009

A Facile Method For The Preparation Of Poly(4-Vinylpyridine) Nanoparticles And Their Characterization, Nurettin Sahiner

Turkish Journal of Chemistry

Submicron size particles were synthesized from 4-vinylpyridine (4-VP) using an oil-in-water emulsion system. Divinyl benzene (DVB) and ethylene glycol dimethacrylate (EGDMA) were utilized as crosslinkers for the synthesis of p(4-VP) hydrogel nanoparticles in sodium dodecyl sulfate (SDS) surfactant systems. Characterization of the particles was made by transmission electron microscopy (TEM) and dynamic light scattering (DLS) methods. To render a positive charge, p(4-VP) particles were reacted with 1-bromo butane (1-BB).

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Synthesis And Leishmanicidal Evaluation Of Novel 4-Substituted-2,2-Dimethyl-7-(Prop-2-Ynyloxy)Chromenes, Babak H. Alizadeh, Alireza Foroumadi, Susan K. Ardestani, Fatemeh Poorrajab, Abass Shafiee Jan 2009

Synthesis And Leishmanicidal Evaluation Of Novel 4-Substituted-2,2-Dimethyl-7-(Prop-2-Ynyloxy)Chromenes, Babak H. Alizadeh, Alireza Foroumadi, Susan K. Ardestani, Fatemeh Poorrajab, Abass Shafiee

Turkish Journal of Chemistry

Substituted 4-chromenes were synthesized via the Grignard coupling reaction of various substituted phenyl- and benzylmagnesium chlorides with 2,2-dimethyl-7-(prop-2-ynyloxy)chroman-4-one (1) in relatively good yield (60%-85%). The benzylic-substituted derivatives were a mixture of 2 exo and endo regioisomers, and the exo compounds were a mixture of E and Z isomers. Structural analysis of the exo and endo isomers, as well as E and Z of exo isomers were based on H-NMR, ^{13}C-NMR, and NOESY experiments. The synthetic compounds were examined for in vitro activity against Leishmania major and compound 9 (a, b) was the most active, with inhibitory activity of 36%.

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Ctab-Assisted Hydrothermal Synthesis And Magnetic Characterization Of Ni_Xco_{1-X}Fe_2o_4 Nanoparticles (X = 0.0, 0.6, 1.0), Abdulhadi̇ Baykal, Nermi̇n Kasapoğlu, Zehra Durmuş, Hüseyi̇n Kavas, Muhammet S. Toprak, Yüksel Köseoğlu Jan 2009

Ctab-Assisted Hydrothermal Synthesis And Magnetic Characterization Of Ni_Xco_{1-X}Fe_2o_4 Nanoparticles (X = 0.0, 0.6, 1.0), Abdulhadi̇ Baykal, Nermi̇n Kasapoğlu, Zehra Durmuş, Hüseyi̇n Kavas, Muhammet S. Toprak, Yüksel Köseoğlu

Turkish Journal of Chemistry

Nickel ferrite, Ni_xCo_{1-x}Fe_2O_4, NPs (where x = 0.0, 0.6 and 1.0) were successfully synthesized by a rapid and reproducible CTAB-assisted hydrothermal route. The influence of different hydrolyzing agents on the particle size and magnetic behavior of Ni_xCo_{1-x}Fe_2O_4 NPs was investigated. Particles showed very high phase purity and crystallinity in powder XRD analysis. Compositions of Co, Fe, and Ni in fabricated powders were also determined by AAS and results are in very good agreement with the targeted compositions. Samples hydrolyzed using NH_3 showed no significant changes in the particle size and morphology. NH_3 hydrolyzed samples were much smaller than their NaOH …

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Mild And Efficient Iodination Of Aromatic Compounds With Trichloroisocyanuric Acid/I_2/Wet Sio_2 System, Batool Akhlaghinia, Marzieh Rahmani Jan 2009

Mild And Efficient Iodination Of Aromatic Compounds With Trichloroisocyanuric Acid/I_2/Wet Sio_2 System, Batool Akhlaghinia, Marzieh Rahmani

Turkish Journal of Chemistry

Iodoarenes can be obtained using trichloroisocyanuric acid/I_2/wet SiO_2 system at room temperature with high yield in CH_2Cl_2.

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Silver Ion-Assisted Ring Expansions In Different Solvent Systems, Mesut Boz, Hafi̇ze Çalişkan, Ömer Zai̇m Jan 2009

Silver Ion-Assisted Ring Expansions In Different Solvent Systems, Mesut Boz, Hafi̇ze Çalişkan, Ömer Zai̇m

Turkish Journal of Chemistry

Several ring expansion products carrying vinylic bromo functionality were synthesized by opening of the geminal dibromobicyclo[n.1.0]alkanes ring. Dibromocarbene was formed from bromoform and potassium tert-butoxide in hexane. Its reaction with various cyclic alkenes was the resultant dibromobicyclo[n.1.0]alkanes. Then, opening was performed using AgNO_3 in various solvent systems, such as acetic acid/DMSO, acetic acid/DMF, CH_3OH/acetone, and H_2O/DMF.

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Bromination Of Tetrachlorobenzobarrelene: Polyhalogenated Benzobicyclics, Mehmet Emi̇n Şengül, Demet Demi̇rci̇ Gülteki̇n, Selçuk Eşsi̇z, Ari̇f Daştan Jan 2009

Bromination Of Tetrachlorobenzobarrelene: Polyhalogenated Benzobicyclics, Mehmet Emi̇n Şengül, Demet Demi̇rci̇ Gülteki̇n, Selçuk Eşsi̇z, Ari̇f Daştan

Turkish Journal of Chemistry

The low and high temperature bromination reaction of tetrachlorobenzobarrelene was studied and the possible role of a neighboring group in rearrangements was investigated. New polyhalogenated benzobicyclic compounds were synthesized. All compounds were characterized properly using NMR spectroscopy.

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Rapid Synthesis Of New Poly(Amide-Imide)S Based On N-(4-Carboxy Phenyl) Trimellitimide And Hydantoin Derivatives Under Microwave Irradiation, Khalil Faghihi, Mohammad Gholizadeh Jan 2009

Rapid Synthesis Of New Poly(Amide-Imide)S Based On N-(4-Carboxy Phenyl) Trimellitimide And Hydantoin Derivatives Under Microwave Irradiation, Khalil Faghihi, Mohammad Gholizadeh

Turkish Journal of Chemistry

Six new poly (amide-imide)s (6a-f) were prepared under microwave irradiation by polycondensation reaction of diacid chloride (4) with 6 different derivatives of hydantoins (5a-f) using O-cresol as a microwave absorbent. These new PAIs were obtained in high yield and with inherent viscosities between 0.15 and 0.25 dL/g. The resulting poly(amide-imide)s were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA & DTG), solubility test, and FT-IR spectroscopy. N-(4-chlorocarbonyl phenyl) trimellitimide acid chloride (4) was prepared by a 2-step reaction. First trimellitic anhydride (1) was reacted with 4-amino benzoic acid (2) in acetic acid solution and the resulting imide-acid [N-(4-carboxy …

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Synthesis And Characterization Of Tetraoxime Ligand, Bis-[(2e,3e,2´E)-3,3´-(1,2-Phenylene-Dinitrilo)Dibutan-2-One Dioxime] And Its Dinuclear And Tetranuclear Copper(Ii)/Nickel(Ii) Complexes, Nevi̇n Karaböcek, Pinar Ekmekçi̇oğlu, Asligül Küçükdumlu, Serdar Karaböcek Jan 2009

Synthesis And Characterization Of Tetraoxime Ligand, Bis-[(2e,3e,2´E)-3,3´-(1,2-Phenylene-Dinitrilo)Dibutan-2-One Dioxime] And Its Dinuclear And Tetranuclear Copper(Ii)/Nickel(Ii) Complexes, Nevi̇n Karaböcek, Pinar Ekmekçi̇oğlu, Asligül Küçükdumlu, Serdar Karaböcek

Turkish Journal of Chemistry

A new tetraoxime, (H_4L), was prepared in EtOH by reacting biphenyl-3,3´,4,4´-tetramine with butane-2,3-dione oxime. The tetraoxime ligand was characterized by elemental analyses, H-NMR and ^{13}C-NMR, IR, and mass spectral studies. Dinuclear copper(II), nickel(II) and tetranuclear copper(II) complexes of tetraoxime ligand were prepared and characterized by elemental analyses, magnetic moments, IR, and mass spectral studies. In the dinuclear metal complexes, metal:ligand ratio was found as 2:1. Elemental analyses and stoichiometric and spectroscopic data of the metal complexes indicated that the metal ions were coordinated to the nitrogen atoms of oxime groups (C=N). In addition, total energy and heat formation for ligand …

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Nitric Oxide Releasing Derivatives Of [(2-Chloroethyl)Ureido] Benzoic Acid Esters As Potential Antineoplastic Agents, Hülya Akgün, Barkin Berk, Di̇lek Demi̇r Erol, Güldem Mercanoğlu, Ömer Faruk Bayrak, Berrak Çağlayan, Asli Dedeağaç, Işil Aksan Kurnaz Jan 2009

Nitric Oxide Releasing Derivatives Of [(2-Chloroethyl)Ureido] Benzoic Acid Esters As Potential Antineoplastic Agents, Hülya Akgün, Barkin Berk, Di̇lek Demi̇r Erol, Güldem Mercanoğlu, Ömer Faruk Bayrak, Berrak Çağlayan, Asli Dedeağaç, Işil Aksan Kurnaz

Turkish Journal of Chemistry

New series of [(2-chloroethyl)ureido] benzoic acids (compounds 3-8) and nitric oxide releasing derivatives of [(2-chloroethyl)ureido] benzoic acid esters (compounds 9-14) were synthesized as potential anti-cancer agents. These compounds were screened for their anti-proliferative activities on A549 (human lung carcinoma) cells and for their cytotoxic effects on L929 (mouse fibroblast) cells. The compounds 3-8 exhibited mild cytotoxic effects on L929 cells (cell viability from 100% to 85% -- 90% only) whereas they had very little anti-proliferative activities towards A549 lung carcinoma cells. On the other hand, compounds 10, 11, and 13 had some growth inhibition activity in A549 (human lung carcinoma) …

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Microwave-Assisted Synthesis Of Some Metal-Free Phthalocyanine Derivatives And A Comparison With Conventional Methods Of Their Synthesis, Özlem Seven, Bi̇rcan Di̇ndar, Burak Gülteki̇n Jan 2009

Microwave-Assisted Synthesis Of Some Metal-Free Phthalocyanine Derivatives And A Comparison With Conventional Methods Of Their Synthesis, Özlem Seven, Bi̇rcan Di̇ndar, Burak Gülteki̇n

Turkish Journal of Chemistry

Synthesis of metal-free 2,9(10),16(17),23(24)-tetra(3,5- dimethylphenoxy) phthalocyanine, 2,9(10),16(17), 23(24)-tetra(4- tert-butylphenoxy) phthalocyanine, and 2,9(10),16(17),23(24)-tetra(3,5- di-tert-butyl-4-hydroxyphenyl) phthalocyanine was carried out via microwave irradiation. Furthermore, pentanol and lithium were used for the first time in the synthesis of metal-free phthalocyanine under microwave irradiation as a solvent and a base-catalyst, respectively. The microwave irradiation experiments were performed in a MARS5 with a CEM XP-1500 vessel. In addition, these compounds were obtained with conventional heating procedures to compare them with those obtained with microwave irradiation. The compounds were characterized by elemental and spectroscopic analysis, including UV-Vis, H NMR, FT-IR, and MALDI-TOF mass data. In particular, both …

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Chiral Calixarenes, Abdulkadi̇r Sirit, Mustafa Yilmaz Jan 2009

Chiral Calixarenes, Abdulkadi̇r Sirit, Mustafa Yilmaz

Turkish Journal of Chemistry

No abstract provided.

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