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Articles 9031 - 9060 of 10317
Full-Text Articles in Physical Sciences and Mathematics
Distribution And Origin Of Clay Minerals In Konya Neogene Sedimentary Basin, Central Anatolia, Turkey, Selahatti̇n Kadi̇r, Zehra Karakaş
Distribution And Origin Of Clay Minerals In Konya Neogene Sedimentary Basin, Central Anatolia, Turkey, Selahatti̇n Kadi̇r, Zehra Karakaş
Turkish Journal of Earth Sciences
Neogene sediments having both fluvial and lacustrine characteristics are widespread in the Konya region of central Anatolia. The fluvial units are typically green in colour and thick at the margin of the basin and thinning laterally basinwards. The lacustrine sediments are represented by white, beige and cream, pure, dolomitic, sandy and clayey limestone alternating with claystone. Grain size, components and matrix of the fluvial and lacustrine sediments decrease from the margin of the basin toward its center. Smectite and chlorite in detrital fluvial sediments are associated with amphibole, illite and quartz, while sepiolite and palygorskite formed diagenetically in the carbonate …
Kinetic Spectrophotometric Determination Of Nanogram Levels Of Manganese (Ii) By Azo Dye -- Potassium Periodate -- 1,10-Phenanthroline System, Konstantin L. Mutaftchiev
Kinetic Spectrophotometric Determination Of Nanogram Levels Of Manganese (Ii) By Azo Dye -- Potassium Periodate -- 1,10-Phenanthroline System, Konstantin L. Mutaftchiev
Turkish Journal of Chemistry
The catalytic effect of manganese (II) on the oxidation of 3 - Methyl - 6 - (2 - hydroxyethoxy) - 2 - [2 - methoxy - 4 - N (N,N - diethylamino) phenylazo] benzothiazolium methylsulphate (MHMDPBM), with potassium periodate in the presence of 1,10-phenanthroline in weakly acidic media was studied. The reaction was followed spectrophotometrically by measuring the decrease in the absorbance of the dye at 560 nm. Under the optimum conditions (4x10^{- 5} mol dm^{- 3} MHMDPBM, 4x10^{- 4} mol dm^{- 3} potassium periodate, 1x10^{- 4} mol dm^{- 3} 1,10-phenanthroline, 0.1 mol dm^{- 3} buffer -- pH 3.0, 70^oC, …
Asymptotic Analysis Of Singularly Perturbed Abstract Evolution Equations In Banach And Hilbert Spaces, Dialla Konate
Asymptotic Analysis Of Singularly Perturbed Abstract Evolution Equations In Banach And Hilbert Spaces, Dialla Konate
Turkish Journal of Mathematics
In the current paper, we are concerned with the study of abstract linear evolution equations in Banach spaces in which the time derivative term is multiplied by a small parameter, say \epsilon. Such equations arise in the study of radiative transfer and neutron transport in Nuclear Physics. Following works by Krein (cf [9]) and others, Mika (cf [12,13,14,15]) using either the Hilbert method or the Compressed method has shown that the solution of the given singularly perturbed equation may be approximated upto any prescibed order by a sum of two asymptotic expansions that are the outer expansion that is valid …
The Fine Spectra Of The Rhaly Operators On C_{0}, Mustafa Yildirim
The Fine Spectra Of The Rhaly Operators On C_{0}, Mustafa Yildirim
Turkish Journal of Mathematics
In 1975, Wenger [3] determined the fine spectra of Cesàro operator C_{1} on c, the space of convergent sequences. In [6], the spectrum of the Rhaly operators on c_{0} and c, under the assumption that {\displaystyle\lim_{n \rightarrow \infty}(n+1)a_{n} }=L\neq 0, has been determined. This paper presents the fine spectra of the Rhaly matrix R_{a} as an operator on the space c_{0}, with the same assumption.
On Some Class Of Hypersurfaces In \Bbb{E}^{N+1} Satisfying Chen's Equality, Ci̇han Özgür, Kadri̇ Arslan
On Some Class Of Hypersurfaces In \Bbb{E}^{N+1} Satisfying Chen's Equality, Ci̇han Özgür, Kadri̇ Arslan
Turkish Journal of Mathematics
In this paper we study pseudosymmetry type hypersurfaces in the Euclidean space \Bbb{E}^{n+1} satisfying B. Y. Chen's equality.
On The Modular Curve X(6) And Surfaces Admitting Genus 2 Fibrations, Gülay Karadoğan
On The Modular Curve X(6) And Surfaces Admitting Genus 2 Fibrations, Gülay Karadoğan
Turkish Journal of Mathematics
In this paper, we study the moduli spaces of surfaces admitting nonsmooth genus 2 fibrations with slope \lambda = 6 (necessarily) over curves of genus \geq 1. We determine the structure of each connected component of these moduli spaces. Our results fill the gap of earlier work in the literature to complete the picture of the moduli spaces of genus 2 fibrations over curves of genus \geq 2 except for the case of \lambda = 4.
On Derivations Of Prime Gamma Rings, Mehmet Ali̇ Öztürk, Young Bae Jun, Kyung Ho Kim
On Derivations Of Prime Gamma Rings, Mehmet Ali̇ Öztürk, Young Bae Jun, Kyung Ho Kim
Turkish Journal of Mathematics
We consider some results in a \Gamma-ring M with derivation which is related to Q, and the quotient \Gamma-ring of M.
Electrochemical Investigation Of 4'-Haloderivatives Of N,N-Dimethyl-4-Aminoazobenzene, Mustafa Uçar, Ali̇ Osman Solak, M. Levent Aksu, Mehmet Toy
Electrochemical Investigation Of 4'-Haloderivatives Of N,N-Dimethyl-4-Aminoazobenzene, Mustafa Uçar, Ali̇ Osman Solak, M. Levent Aksu, Mehmet Toy
Turkish Journal of Chemistry
In this study, the electrochemical behaviour of 4' -halogene-N,N-dimethyl-4-aminoazobenzene derivatives were investigated using various polarographic and voltammetric methods. The peak potentials of these derivatives were observed to shift towards negative values with increase in pH. The standard rate constants were determined with (Laviron technique) or without (Nicholson and Klingler-Kochi techniques) taking the adsorption phenomena into account. The diffusion coefficients were calculated from the cyclic voltammetric data using the method developed by Garrido. The amount of adsorbed substances (surface excess values) and transfer coefficients for the electron transfer were also determined. These compounds can be quantitatively determined between 1 x 10^{-5} …
Walkthrough In Complex Environments At Interactive Rates Using Level-Of-Detail, Alper Selçuk, Uğur Güdükbay, Bülent Özgüç
Walkthrough In Complex Environments At Interactive Rates Using Level-Of-Detail, Alper Selçuk, Uğur Güdükbay, Bülent Özgüç
Turkish Journal of Electrical Engineering and Computer Sciences
One of the biggest problems in computer graphics is displaying huge geometric models at interactive rates. A lot of work has been done to achieve the required frame-rates in architecture, simulation, computer-aided design and entertainment applications. In this paper, a system that enables walkthrough in complex environments using level-of-detail approximations is explained. The system uses hierarchical triangulated models as input. In the preprocessing phase, multiresolution models of objects are created using polygonal simplification techniques. During walkthrough, fast frustum culling based on bounding boxes is performed to eliminate branches of hierarchy that are not visible. An appropriate level for detail of …
A New Petri-Net-Based Synthesis Technique For Supervisory Control Of Discrete Event Systems, Murat Uzam, Anthony H. Jones
A New Petri-Net-Based Synthesis Technique For Supervisory Control Of Discrete Event Systems, Murat Uzam, Anthony H. Jones
Turkish Journal of Electrical Engineering and Computer Sciences
A new Petri-net-based top-down synthesis technique for supervisory control of Discrete Event Systems (DES) is proposed to solve the forbidden state problem. The supervisors obtained are compiled supervisors, whose control policy is represented as a net structure, as opposed to mapping supervisors, whose control policy is computed as a feedback function of the marking of the system. The compiled supervisors obtained by using the technique proposed in this paper are both nonblocking and maximally permissive. The supervisors to be synthesised consist of a controlled Automation Petri Net model of the system. Automation Petri Nets (APN) include the following extensions to …
New Oscillator Topologies Using Inverting Second-Generation Current Conveyors, Ali̇ Toker, Hakan Kuntman, Oğüzhan Çi̇çekoğlu, Mehmet Di̇şçi̇gi̇l
New Oscillator Topologies Using Inverting Second-Generation Current Conveyors, Ali̇ Toker, Hakan Kuntman, Oğüzhan Çi̇çekoğlu, Mehmet Di̇şçi̇gi̇l
Turkish Journal of Electrical Engineering and Computer Sciences
In this work, new oscillator topologies based on a recently introduced active element, namely inverting second-generation current conveyor, are presented. This recently introduced unity gain based active element is suitable for integrated circuit realization and can easily be implemented with CMOS technology. Considering this fact, basic oscillator topologies employing a single, two and three conveyors are proposed. Several oscillator circuits based on these topologies are obtained. Expressions for oscillation conditions and frequencies are derived both for ideal and non-ideal cases. Some of them are single frequency and the others are variable frequency oscillators. The oscillators employing two and three active …
Floquet Wave Diffraction Theory For Tapered Planar Strip Array Green's Function, F. Capolino, F. Mariottini, S. Maci, L. B. Felsen
Floquet Wave Diffraction Theory For Tapered Planar Strip Array Green's Function, F. Capolino, F. Mariottini, S. Maci, L. B. Felsen
Turkish Journal of Electrical Engineering and Computer Sciences
This paper deals with the derivation and physical interpretation of a uniform high frequency representation of the Green's function for a planar phased array of dipoles. The asymptotic representation is based on Floquet wave edge diffraction theory herein extended to accommodate slowly varying tapered amplitude illumination with possible inclusion of dipole amplitudes that tend to zero at the edge. The phased array is assumed to be infinite with uniform amplitude excitation in the z-direction but finite and amplitude-tapered in the x-direction. This geometry permits study of diffraction phenomena occurring at the tapered edge of a rectangular array when the observation …
An Exact Line Integral Representation Of The Po Radiation Integral From A Flat Perfectly Conducting Surfaces Illuminated By Elementary Electric Or Magnetic Dipoles, Matteo Albani, Stefano Maci
An Exact Line Integral Representation Of The Po Radiation Integral From A Flat Perfectly Conducting Surfaces Illuminated By Elementary Electric Or Magnetic Dipoles, Matteo Albani, Stefano Maci
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a line integral representation for the PO radiation integral from a flat perfectly conducting surface, illuminated by an arbitrary oriented elementary either electric or magnetic dipole, is presented. No restriction is imposed on the position of the source and of the observation point. The main application of this result is the acceleration of the numerical PO integration for electrically large surfaces. The formulation is based on the application of the equivalence principle to a projecting surface which allows the analytical evaluation in closed form of one of the two-fold surface integral which define the radiated field at …
Development Of A Cylindrical Waveguide Antenna Array With A High Isolation Between Receive - Transmit Sub Arrays: Theory And Experiment, Vladimir I. Okhmatovsky, Konstantina S. Nikita, Stavros Koulouridis, Nikolaos K. Uzunoglu
Development Of A Cylindrical Waveguide Antenna Array With A High Isolation Between Receive - Transmit Sub Arrays: Theory And Experiment, Vladimir I. Okhmatovsky, Konstantina S. Nikita, Stavros Koulouridis, Nikolaos K. Uzunoglu
Turkish Journal of Electrical Engineering and Computer Sciences
The possibility of developing an antenna system consisting of transmit and receive arrays and being able to work simultaneously in full duplex mode at the same frequency is a very attractive task. This could only be achieved if the isolation between the transmit and receive arrays is sufficiently high not to cause a parasitic oscillation which will ruin the proper operation of a transponder system to which the arrays will be connected. Specifically, in this paper the operation of two peripheral open waveguide arrays placed on a cylindrical surface and being isolated with a radial line operating as a space …
A Time Domain Uniform Geometrical Theory Of Slope Diffraction For A Curved Wedge, Prabhakar H. Pathak, Paul R. Rousseau
A Time Domain Uniform Geometrical Theory Of Slope Diffraction For A Curved Wedge, Prabhakar H. Pathak, Paul R. Rousseau
Turkish Journal of Electrical Engineering and Computer Sciences
A time domain version of the uniform geometrical theory of diffraction (TD-UTD) is developed to describe, in essentially closed form, the field which is produced via slope diffraction at a perfectly conducting, arbitrarily curved wedge excited by a time impulsive wave that exhibits a rapid spatial variation near the edge of the wedge. This TD-UTD slope diffracted field for a curved wedge is obtained by a Fourier inversion of the corresponding frequency domain UTD expression. An analytical signal representation of the transient fields is used since it is convenient, and because it circumvents some of the difficulties, which especially arise …
Scalar Wave Diffraction By Perfectly Soft Thin Circular Cylinder Of Finite Length; Analytical Regularization Method, Eylem Özkan, Fati̇h Di̇kmen, Yury Alexanderovich Tuchkin
Scalar Wave Diffraction By Perfectly Soft Thin Circular Cylinder Of Finite Length; Analytical Regularization Method, Eylem Özkan, Fati̇h Di̇kmen, Yury Alexanderovich Tuchkin
Turkish Journal of Electrical Engineering and Computer Sciences
A new mathematically rigorous and numerically effective method for solving the boundary value problem of scalar wave diffraction by an infinitely thin circular cylindrical screen of finite length is proposed. The method is based on the combination of the Orthogonal Polynomials Approach, and on the ideas of the methods of analytical regularization. As a result of the suggested regularization procedure, the initial boundary value problem is equivalently reduced to the infinite system of the linear algebraic equations of the second kind, i.e. to an equation of the type (I + H)x = b in the space \ell _{2} of square …
Active Clamped Zvs Forward Converter With Soft-Switched Synchronous Rectifier, A. Açik, Işik Çadirci
Active Clamped Zvs Forward Converter With Soft-Switched Synchronous Rectifier, A. Açik, Işik Çadirci
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents the analysis, design and implementation of an active-clamped, ZVS forward converter equipped with a soft-switched synchronous rectifier (ACFC-SR) proposed for high-efficiency, low output voltage dc-dc converter applications. The converter efficiency is maximized due to the soft-switching of the main, active clamp, synchronous rectifier and freewheeling MOSFET switches. The operating principles of the ACFC-SR are analyzed in detail and the converter performance is compared with the alternative forward converter schemes employed in low output voltage dc-dc converters. Experimental results are presented for a converter with a dc input voltage of 48 V, an output voltage of 5 V, …
Electromagnetic Engineering In The 21^{St} Century: Challenges And Perspectives, Leopold B. Felsen, Levent Sevgi̇
Electromagnetic Engineering In The 21^{St} Century: Challenges And Perspectives, Leopold B. Felsen, Levent Sevgi̇
Turkish Journal of Electrical Engineering and Computer Sciences
This paper aims at a broad-brush look at certain technological and educational challenges that confront wave-oriented electromagnetic (EM) engineering in the 21^{st} century, in a complex computer and technology-driven world with rapidly shifting societal and technical priorities. Simulation strategies for complex EM systems, both analytic and numerical, are reviewed and categorized, and are illustrated on selected practical complex multicomponent system scenarios currently under investigation in Turkey. Educational issues to ensure proper multidisciplinary exposure of new generations of computer-weaned students, who will have to deal with these problems, are touched upon as well.
Time-Domain Simulation Of Thin Material Boundaries And Thin Panels Using Digital Filters In Tlm, J. Paul, V. Podlozny, Dave Thomas, C. Christopoulos
Time-Domain Simulation Of Thin Material Boundaries And Thin Panels Using Digital Filters In Tlm, J. Paul, V. Podlozny, Dave Thomas, C. Christopoulos
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, the design and implementation of digital filters for the time-domain simulation of electromagnetic wave interaction with thin material boundaries and thin panels using the Transmission-Line Modelling (TLM) method are described. The technique is applied to the description of thin ferrite layers placed on the external boundaries of the modelled space and to plastic panels placed inside the modelled space. The approach is validated using one-dimensional examples having analytic solutions. Finally, the results obtained for the Shielding Effectiveness (SE) of a practical equipment enclosure are presented to demonstrate the utility of the method in Electromagnetic Compatibility (EMC) prediction.
An Efficient Preconditioner For Iterative Solvers, V. V. S. Prakash, Raj Mittra
An Efficient Preconditioner For Iterative Solvers, V. V. S. Prakash, Raj Mittra
Turkish Journal of Electrical Engineering and Computer Sciences
The method of moments solution of the Maxwell's equations leads to a dense system of complex equations. Direct solution of these equations using LU factorization becomes unwieldy as the size of the scatterer increase in terms of wavelength. Iterative solvers, such as those based on Krylov projection methods, offer an alternative approach for solving large system of equations. Most often, the iterative methods are used in combination with some kind of preconditioning to improve the condition number of the system matrix A in order to acheive accelerated convergence [1-2]. This paper discusses the application of Multi-Frontal Preconditioners (MFPs) for the …
Iridoid, Phenylethanoid And Monoterpene Glycosides From Phlomis Sieheana, Tayfun Ersöz, Ü. Şebnem Harput, İhsan Çaliş, Ali̇ Arslan Dönmez
Iridoid, Phenylethanoid And Monoterpene Glycosides From Phlomis Sieheana, Tayfun Ersöz, Ü. Şebnem Harput, İhsan Çaliş, Ali̇ Arslan Dönmez
Turkish Journal of Chemistry
From the aerial parts of Phlomis sieheana, an iridoid glucoside, ipolamiide (1), six phenylethanoid glycosides, acteoside (= verbascoside) (2), cis-acteoside (3), \beta-hydroxyacteoside (4), leucosceptoside A (5), martynoside (6), forsythoside B (7), and a monoterpene glycoside, betulalbuside A (8) were isolated and characterized. The structure elucidations of the isolated compounds were established on the basis of spectroscopic evidence.
Determination Of Trace Amounts Of Gold(Iii) Using Ethopropazine Hydrochloride And Isothipendyl Hydrochloride: A Spectrophotometric Study, Mahaveer B. Melwanki, Saraswati̇ P. Masti, Jaldappa Seetharamappa
Determination Of Trace Amounts Of Gold(Iii) Using Ethopropazine Hydrochloride And Isothipendyl Hydrochloride: A Spectrophotometric Study, Mahaveer B. Melwanki, Saraswati̇ P. Masti, Jaldappa Seetharamappa
Turkish Journal of Chemistry
Two simple, sensitive and accurate spectrophotometric methods have been proposed for the determination of micro amounts of gold (III) using ethopropazine hydrochloride (EPH) and isothipendyl hydrochloride (IPH). The methods are based on the oxidation of phenothiazines by gold (III) to give red radical cations having maximum absorption at 513 and at 512 nm with molar absorptivities of 2.0 X 10^{4} and 2.1 X 10^{4} l mol^{ - 1} cm^{ - 1} for EPH and IPH respectively. Beer's law is valid over the concentration range 0.5-14.1 mg l^{ - 1} for EPH and 0.5-14.5 mg l^{ - 1} for IPH. The …
Electron Ionization Mass Spectrometric Studies Of Homalicine Tertraacetate, Dihydrohomalicine Tetraacetate And Related Compounds, Nasim Hasan Rama, Muhammad Tahir Hussain
Electron Ionization Mass Spectrometric Studies Of Homalicine Tertraacetate, Dihydrohomalicine Tetraacetate And Related Compounds, Nasim Hasan Rama, Muhammad Tahir Hussain
Turkish Journal of Chemistry
Electron Ionization mass spectra of homalicine tetraacetate (3), dihydrohomalicine tetraaetate (4) and related compounds (5,6) are described with the help of EIMS. The molecular formulae are further confirmed by HREIMS peak matching of molecular ion peaks exhibited by EIMS.
Automated Recognition Of Ergogenic Aids Using Soft Independent Modeling Of Class Analogy (Simca), M. Praisler, J. Van Bocxlaer, A. De Leenheer, D. L. Massart
Automated Recognition Of Ergogenic Aids Using Soft Independent Modeling Of Class Analogy (Simca), M. Praisler, J. Van Bocxlaer, A. De Leenheer, D. L. Massart
Turkish Journal of Chemistry
The introduction of effective drug testing procedures in doping control reduced, but did not eliminate, their abuse by athletes. The most important analytical challenge is the recognition of the new analog compounds. In attempts to circumvent existing controlled substance laws, slightly modified chemical structures (by adding or changing substituents at various positions on the banned molecules) are used. As a result, no substance belonging to a prohibited class may be used nowadays, even if it has not been specifically listed. We present a chemometric procedure acting as an automated GC-FTIR screening test detecting the molecular structural similarity of unknown compounds …
Determination Of Manganese And Iron In Magmatic Rocks After Ultrasonic Leaching By Flame Aas, M. Hi̇kmet Özkan, Mehmet Akçay
Determination Of Manganese And Iron In Magmatic Rocks After Ultrasonic Leaching By Flame Aas, M. Hi̇kmet Özkan, Mehmet Akçay
Turkish Journal of Chemistry
An alternative sample preparation method has been developed for destructive analysis of magmatic rock sample. The method simply included the crushing, HF treatment and 1% HCl leaching steps of the rock samples under ultrasonic effects. There is no need to exhaust all of the sample through the operation. A reproducible and representative, partial recovery of an analyte was expected in a procedural sequences consisting of strictly defined steps. The changes in analyte recoveries were investigated by sample grain size, sample mass, applied ultrasonic power and sonication time. The optimum recovery conditions were examined. In addition, the kinetics of the dissolution …
Extraction Equilibria Of Nicotinic Acid Using Alamine 300/Diluent And Conventional Solvent Systems, Aynur Şenol
Extraction Equilibria Of Nicotinic Acid Using Alamine 300/Diluent And Conventional Solvent Systems, Aynur Şenol
Turkish Journal of Chemistry
The distribution of nicotinic acid between water and Alamine 300 (tri-n-octylamine) dissolved in various (proton-donating and -accepting, polar and nonpolar) diluents, and a comparison with the extraction equilibria of pure diluent alone were studied at 298 K and a phase ratio of 1:1 (v/v). The cyclic alcohol/amine system yielded the highest synergistic extraction efficiency. The strength of the complex solvation was found to be reasonably high for halogenated aliphatic hydrocarbons and nitrobenzene, activating mainly the formation of the acid_{1}-amine_{1} structure. The influence of the acid structure over distribution was evaluated through comparing the extractabilities of three acids containing different functional …
Dehydration Behaviour Of Borax Pentahydrate To Anhydrous Borax By Multi-Stage Heating In A Fluidized, Ömer Şahi̇n, A. Nusret Bulutcu
Dehydration Behaviour Of Borax Pentahydrate To Anhydrous Borax By Multi-Stage Heating In A Fluidized, Ömer Şahi̇n, A. Nusret Bulutcu
Turkish Journal of Chemistry
In order to optimize the anhydrous borax process in a fluidized bed calcinator, it is absolutely necessary to study the dehydration behaviour of borax pentahydrate. It was found that the basic feature of the dehydration of borax pentahydrate to anhydrous borax is concerned with the conditions employed. The bulk density and sodium borate content of the end product were determined to be a function of number of stages of temperature of the dehydration period in the fluidized bed. It was observed that bulk density also depends on the number of moles of water remaining in the borax pentahydrate structure. High …
Partially Purification And Characterization Of Polyphenol Oxidase Of Quince, Hülya Yağar, Ayten Sağiroğlu
Partially Purification And Characterization Of Polyphenol Oxidase Of Quince, Hülya Yağar, Ayten Sağiroğlu
Turkish Journal of Chemistry
Polyphenol oxidase (PPO, EC 1.14.18.1) was extracted from quince (Cydonia oblonga) by using 0.1 M phosphate buffer, pH 6.8. The polyphenol oxidase of quince was partially purified by (NH_{4})_{2}SO_{4} and dialysis. Substrate specificity experiments were carried out with catechol, pyrogallol, L-DOPA, p-cresole and tyrosine. Catechol was the most suitable substrate compound for quince PPO. The Michaelis constants were 4.54 mM, 7.35mM and 17.8 mM for catechol, pyrogallol and L-DOPA, respectively at 25^oC. The optimum pH and temperature were determined with the specific substrate catechol as 8.0 and 40$^oC, respectively. Of eight inhibitors tested L-cysteine, ascorbic acid and potassium cyanide were …
Vibrational Spectra And Assignments Of Cis- And Trans-1,4-Polybutadiene, P. Nallasamy, P.M. Anbarasan, S. Mohan
Vibrational Spectra And Assignments Of Cis- And Trans-1,4-Polybutadiene, P. Nallasamy, P.M. Anbarasan, S. Mohan
Turkish Journal of Chemistry
The Raman spectra of cis- and trans-1,4- polybutadiene were recorded in the region 100-4000 cm^{-1} and its infrared spectra were also measured in the wave number range 200--4000 cm^{-1}. The spectra were completely analysed. Probable assignments to observed bands were made with the help of intensities and normal co-ordinate analysis. The calculated normal frequencies were in good agreement with the experimental ones.
An Investigation Of Some Parameters On Electrorheological Properties Of Polypyrrole Suspensions, Deni̇z Şahi̇n, Beki̇r Sari, Hali̇l İbrahi̇m Ünal
An Investigation Of Some Parameters On Electrorheological Properties Of Polypyrrole Suspensions, Deni̇z Şahi̇n, Beki̇r Sari, Hali̇l İbrahi̇m Ünal
Turkish Journal of Chemistry
In this study, polypyrrole (PPy) was synthesized by cationic addition polymerization. The polymer was characterized by FTIR spectroscopy, scanning electron microscopy (SEM), particle size, magnetic susceptibility, and four-probe conductivity measurements. From the magnetic susceptibility measurements, it was found that the polymer was a bipolaron conducting mechanism. From the particle size measurements, the average particle size of PPy was determined to be 3.2 \mu m. Suspensions of this polymer were prepared in silicone oil, mineral oil, trioctyltrimellitate (TOTM), dioctylphthalate (DOP) and marlotherm-s in different concentrations (5-20%, m/m). The electrorheological (ER) properties of these suspensions were investigated under various d.c. electric field …