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1998

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Optimization Of Starting Time And Period Of Induction And Inducer Concentration In The Production Of The Restriction Enzyme Ecori From Recombinant Escherichia Coli 294, Candan Yildir Tamerler, Z. İlsen Önsan, Betül Kirdar Jan 1998

Optimization Of Starting Time And Period Of Induction And Inducer Concentration In The Production Of The Restriction Enzyme Ecori From Recombinant Escherichia Coli 294, Candan Yildir Tamerler, Z. İlsen Önsan, Betül Kirdar

Turkish Journal of Chemistry

Induction parameters including inducer concentration, period of induction and the cell concentration at which inducer is to be added to the fermentation broth were optimized in order to increase the yield of the {\em Eco}RI restriction endonuclease isolated from recombinant {\em E. coli}. Bacterial cells harboring the plasmid pPG430 containing {\em Eco}RI endonuclease and the methylase genes under the control of {\em lac} promoter were used in the experiments where induction was accomplished by using lactose isopropyl-$\beta$-D-thiogalactoside (IPTG). An IPTG concentration of 0.1mM, the late exponential phase of growth (at an optical density of 1.2 at 595 nm) and an …

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Indirect Complexometric Determination Of Mercury Using Potassium Iodide As Selective Masking Agent, B. Muralidhara Rao Jan 1998

Indirect Complexometric Determination Of Mercury Using Potassium Iodide As Selective Masking Agent, B. Muralidhara Rao

Turkish Journal of Chemistry

This paper describes a indirect complexometric method for the determination of mercury in the presence of co-ions, based on the selective masking ability of potassium iodide. To the mixture of mercury (II) and other metal ion solution, EDTA solution was added in excess of the metal ions present. The pH of the solution was adjusted to 5.0-6.0 using solid hexamine ($10 \pm 2$ g) and surplus EDTA was titrated with zinc sulfate solution using xylenol orange indicator. An excess of solid potassium iodide was then added to decompose the Hg-EDTA complex and the released EDTA was titrated with standard zinc …

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Crystal Structure Of Dichlorodiaquabis-(P- Dimethylaminobenzaldehyde)Manganese(Ii), Veysel T. Yilmaz, Turan K. Yazicilar, Halis Ölmez, R. Alan Howie Jan 1998

Crystal Structure Of Dichlorodiaquabis-(P- Dimethylaminobenzaldehyde)Manganese(Ii), Veysel T. Yilmaz, Turan K. Yazicilar, Halis Ölmez, R. Alan Howie

Turkish Journal of Chemistry

The crystal structure of dichlorodiaquabis-($p$-dimethylaminobenzaldehyde)manganese(II), [MnCl$_2$(OH$_2$)$_2$(C$_9$H$_{11}$NO)$_2$], was determined from X-ray intensity data. The structure consists of the isolated molecules of the complex. The central Mn atom in the complex is coordinated by txo $p$-dimethylaminobenzaldehyde and two water molecules and also two chlorine atoms, resulting in a distorted octahedral environment. The same molecules or ions occupy {\it trans} positions. The crystal structure is stabilized by weak hydrogen bonds present between the isolated molecules.

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President Clinton And The Rhetoric Of Time, Estrella Cedeno Jan 1998

President Clinton And The Rhetoric Of Time, Estrella Cedeno

Dissertations and Theses @ UNI

This study analyzes President's Clinton 1993 and 1997 inaugural addresses, and his use of time as a rhetorical strategy. Influenced by his situational constraints and based on a definition of the situation that emphasizes time as a paramount element, Clinton is able to articulate an inaugural rhetoric that instead of being passive and contemplative calls for action. In so doing, Clinton's inaugurals finds its uniqueness. I contend that Clinton's rhetoric of time gives meaning to the transformations of the post-industrial revolution and also serves as a form of social control.

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Trace Element Signatures In Otoliths Record Natal River Of Juvenile American Shad (Alosa Sapidissima), Simon R. Thorrold, Cynthia M. Jones, Steven E. Campana, James W. Mclaren, Joseph W. H. Lam Jan 1998

Trace Element Signatures In Otoliths Record Natal River Of Juvenile American Shad (Alosa Sapidissima), Simon R. Thorrold, Cynthia M. Jones, Steven E. Campana, James W. Mclaren, Joseph W. H. Lam

OES Faculty Publications

The elemental composition of fish otoliths may represent a permanent record of the environmental conditions an individual has experienced as trace elements, incorporated into the growing surface of the otolith, reflect the physical and chemical characteristics of the ambient water. We tested the utility of trace element signatures in otoliths as natural tags of the river of origin of juvenile American shad (Alosa sapidissima) collected from the Connecticut, Hudson and Delaware Rivers in August and October 1994. Four elements (K, Mn, Sr, and Ba) showed significant variability among sites within rivers in August, although only Mg showed a …

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Stochastic Analysis Of Quality Control Charts Using Integral Equations, Kenneth Adam Scharnagl Jan 1998

Stochastic Analysis Of Quality Control Charts Using Integral Equations, Kenneth Adam Scharnagl

College of Graduate Studies: Theses & Dissertations (1964–2006)

No abstract provided.

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Rules Of Order: A Biography Of Henry Martyn Robert, Soldier, Engineer, Churchman, Parliamentarian, George Brian Hendricks Jan 1998

Rules Of Order: A Biography Of Henry Martyn Robert, Soldier, Engineer, Churchman, Parliamentarian, George Brian Hendricks

College of Graduate Studies: Theses & Dissertations (1964–2006)

No abstract provided.

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Studies Of Quantum Chromodynamics With The Aleph Detector, R. Barate, M. Thulasidas Jan 1998

Studies Of Quantum Chromodynamics With The Aleph Detector, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

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Evaluation Of Information Modeling Methods: A Review, Keng Siau, Matti Rossi Jan 1998

Evaluation Of Information Modeling Methods: A Review, Keng Siau, Matti Rossi

Research Collection School Of Computing and Information Systems

Hundreds of modeling methods are in existence today. Yet practitioners and researchers are zealously "producing" new modeling methods. The "blooming" of modeling methods is not the problem; the lack of standardize techniques for evaluating them is. To further complicate the matter, most of the modeling methods are introduced based on common sense and intuition. Theoretical foundations and empirical evidence are severely lacking. With the current state of affairs, evaluation of modeling methods has become necessary. Comparing modeling methods provides us with the necessary knowledge and understanding on the strengths and weaknesses of each method. This knowledge can also guide us …

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Armstrong Academics Winter 1998, Armstrong Atlantic State University Jan 1998

Armstrong Academics Winter 1998, Armstrong Atlantic State University

Armstrong State University Collections: Armstrong Academics (Archived)

No abstract provided.

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Armstrong Academics Spring 1998, Armstrong Atlantic State University Jan 1998

Armstrong Academics Spring 1998, Armstrong Atlantic State University

Armstrong State University Collections: Armstrong Academics (Archived)

No abstract provided.

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Undergraduate And Graduate Catalog [1997-1998], Georgia Southern University Jan 1998

Undergraduate And Graduate Catalog [1997-1998], Georgia Southern University

Undergraduate & Graduate Catalogs

No abstract provided.

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A Reassessment Of The Hybrid Approach To The Construction Of Regional Input-Output Tables, Steven Brand Jan 1998

A Reassessment Of The Hybrid Approach To The Construction Of Regional Input-Output Tables, Steven Brand

Plymouth Business School Theses

This thesis lays the foundation for the creation of an economic database for the counties of Devon and Cornwall in the form of a regional input-output table. The thesis reconsiders the popular hybrid approach to the construction of such tables. In particular, the nonsurvey-to-survey ordering of procedure is questioned. The thesis attempts to restore a more logical preference-order which begins with first-best (survey) estimation methods and extends to second-best (survey-based-nonsurvey) methods. The third-best methods of estimation (pure nonsurvey i.e. location quotient) are excluded from the process altogether. The thesis is largely concerned with the development of the second-best method. The …

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Characterization Of An All-Optical Device Based On Organic Materials, Hans-Martin Keller, Mark Andreas Bader, Gerd Marowsky Jan 1998

Characterization Of An All-Optical Device Based On Organic Materials, Hans-Martin Keller, Mark Andreas Bader, Gerd Marowsky

Turkish Journal of Chemistry

We present numerical and first experimental results for an all-optical switching device. The device consists of a periodically modulated nonlinear waveguide, where so-called gap solitons stabilize the switching process. The fabrication of Bragg gratings in different polymeric films, e.g. poly(phenylene vinylene), polydiacetylene or polystyrene by excimer laser photoablation was tested. In preparation of further experiments numerical calculations were performed to characterize the device under realistic conditions, including position dependent index modulations and absorption losses. In further time-dependent simulations the transition from the reflecting to the transparent state was investigated in detail. As a main result, the threshold intensity turns out …

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Intrinsic Semiconducting Materials On Phthalocyanine Basis, Michael Hanack Jan 1998

Intrinsic Semiconducting Materials On Phthalocyanine Basis, Michael Hanack

Turkish Journal of Chemistry

Stacked transition metal macrocycles [MacM(L)]$_n$ with M e.g. Fe, Ru, Os, Co, Rh and Mac = phthalocyanine (Pc) 1,2- or 2,3-naphthalocyanine (1,2-, 2,3-Nc) were synthesized. The bridging ligands (L) may be e.g. pyrazine (pyz) or $s$-tetrazine (tz). In general, these complexes [MacM(L)]$_n$ are insoluble in organic solvents; however, soluble oligomers [R$_4$PcM(L)]$_n$ can be prepared using metallomacrocycles R$_n$PcM, R = $t$-bu, et, OR, M = Fe, Ru, which are substituted in the peripheric positions. A systematic investigation of the influence of the bridging ligands on the semiconducting properties in [MacM(L)]$_n$ reveals that changing L, e.g., from dabco over pyz to tz …

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Phthalocyanines And Related Compounds: Subunits For The Preparation Of Molecular Materials, J. Garcia, A. Gonzalez, A. Gouloumis, E.M. Maya, M.D. Perez, B.D. Rey, P. Vazquez, T. Torres Jan 1998

Phthalocyanines And Related Compounds: Subunits For The Preparation Of Molecular Materials, J. Garcia, A. Gonzalez, A. Gouloumis, E.M. Maya, M.D. Perez, B.D. Rey, P. Vazquez, T. Torres

Turkish Journal of Chemistry

The design, synthesis, structural and physical characterization and engineering, and the study of the electrical conductivity and the nonlinear optical properties of phthalocyanines and molecular substances related to them, such as subphthalocyanines, hemiporphyrazines and triazolephthalocyanines were reviewed.

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Azobenzene Side-Chain Liquid Crystalline Polyesters With Outstanding Optical Storage Properties, S. Hvilsted, M. Pedersen, N.C.R. Holme, P.S. Ramanujan Jan 1998

Azobenzene Side-Chain Liquid Crystalline Polyesters With Outstanding Optical Storage Properties, S. Hvilsted, M. Pedersen, N.C.R. Holme, P.S. Ramanujan

Turkish Journal of Chemistry

A flexible azobenzene side-chain liquid crystalline (SCLC) polyester architecture employed for reversible optical storage is described. The modular design allows four structural parameters to be individually modified. These parameters: {\em i}- the methylene side-chain spacer length, {\em ii}- the substituent on azobenzene, {\em iii}- the methylene main-chain segment length, and {\em iv}- the polyester molecular mass, all influence the optical storage properties. A general synthetic route to novel mesogenic azobenzene diols comprising parameters {\em i} and {\em ii} is outlined. Polyesters with molecular masses (parameter {\em iv}) up to 100,000 are routinely obtained by melt transesterification of the novel diols …

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Electropolymerization Of Thiophene With And Without Aniline In Acetonitrile, Muzaffer Can, Kadir Pekmez, Nuran Pekmez, Attila Yildiz Jan 1998

Electropolymerization Of Thiophene With And Without Aniline In Acetonitrile, Muzaffer Can, Kadir Pekmez, Nuran Pekmez, Attila Yildiz

Turkish Journal of Chemistry

The electrooxidation behaviors of thiophene and 3-methylthiophene on a Pt surface in acetonitrile/tetrabutylammonium tetrafluoroborate solution were investigated using cyclic voltammetry. The electropolymerization of these monomers and electrochemical properties of polythiophene and poly(3-methylthiophene) were studied in neutral, acidic and basic media. Mechanisms related to the formation of polymers and electroactivity loss were proposed. The effect of thiophene on the electropreparation and properties of polyaniline were also investigated. The presence of thiophene in solutions of aniline in acetonitrile accelerates the formation and causes an improvement in the conductivity of polyaniline films. Thiophene, which catalyzes the polyaniline formation, enters into the structure of …

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Xps Investigations On Conducting Polymers, Ş. Süzer, Ö. Bi̇rer, U.A. Sevi̇l, O. Güven Jan 1998

Xps Investigations On Conducting Polymers, Ş. Süzer, Ö. Bi̇rer, U.A. Sevi̇l, O. Güven

Turkish Journal of Chemistry

X-ray photoelectron spectroscopy, XPS, was used for the characterization of electrically conducting polymeric materials. In the spectrum of polypyrrole, PPy, the Nls region exhibits two peaks, at 402.0 and 399.8 eV, corresponding to -N$^+$- and -N- moieties, respectively. The intensity of the N$^+$ peak decreases as the material loses its conductivity, hence the ratio of the experimentally derived N$^+$/C atomic ratio correlates exponentially with the measured conductivity. A similar observation also exists between the F$^-$/C atomic ratio both in polypyrrole and polythiophene. In the XPS spectrum of the composite material prepared using polyaniline, PAN and polyvinylchloride, PVC, two different kinds …

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Electrochromism Of Sol-Gel Derived Niobium Oxide Films, M. Maçek, B. Orel Jan 1998

Electrochromism Of Sol-Gel Derived Niobium Oxide Films, M. Maçek, B. Orel

Turkish Journal of Chemistry

Niobium oxide films are promising cathodic electrochromics that in many aspects can compete with the more frequently studied WO$_3$ films. The films reported herein were prepared using the sol-gel route from a NbCl$_5$ precursor. The electrochromic properties were pronounced for crystalline films that are heat-treated at 500^oC and exhibited transmittance changes between coloured and bleached states of 60 \% in the UV and 80 \% in the VIS-NIR regions. Improved bleaching and more reversible electrochromism of thick niobium oxide films (d $>$ 250 nm) were obtained by lithiation.

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Electrically Conductive Polymer Grafts Prepared By Electrochemical Polymerization Of Pyrrole Onto Poly[(Methyl Methacrylate)-Co-(2-(N-Pyrrolyl) Ethyl Methacrylate)] Electrodes, Nuran Balci, Ural Akbulut, Levent Toppare, Dietmar Stanke, Manfred L. Hallensleben Jan 1998

Electrically Conductive Polymer Grafts Prepared By Electrochemical Polymerization Of Pyrrole Onto Poly[(Methyl Methacrylate)-Co-(2-(N-Pyrrolyl) Ethyl Methacrylate)] Electrodes, Nuran Balci, Ural Akbulut, Levent Toppare, Dietmar Stanke, Manfred L. Hallensleben

Turkish Journal of Chemistry

Pyrrole was grafted on poly[(methyl methacrylate)-co-(2-(N-pyrrolyl) ethyl methacrylate)] (PMMA-co-PEMA) using constant potential electrolyses. The thermal stability of PMMA-co-PEMA was improved as a result of electrochemical grafting with pyrrole. The electrochemical behavior of the films was studied by cyclic voltammetry. Pyrrole was found to be electroactive on PMMA-co-PEMA electrodes.

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Dc Conduction In Electrochemically Synthesized Polypyrrole Films, Akif Kaynak Jan 1998

Dc Conduction In Electrochemically Synthesized Polypyrrole Films, Akif Kaynak

Turkish Journal of Chemistry

DC conductivity measurements were performed by modified four-probe rig on electrochemically synthesized polypyrrole films at a temperature range of -30^oC to 120^oC. Conductivity increased with temperature. The temperature dependence of conductivity was very high for lightly doped polymers, decreasing as the doping level increased. The model used to describe the conduction process was the conduction model originally developed for amorphous silicon by Mott and Davis. When applied to conducting polymers, it assumes that electron transport originates from localized or fixed states within the polymer chain. The charge transfer between the chains takes place by hopping, referred to as phonon-assisted hopping, …

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Dimerization Of Pyrrole, Mine Yurtsever, Ersin Yurtsever Jan 1998

Dimerization Of Pyrrole, Mine Yurtsever, Ersin Yurtsever

Turkish Journal of Chemistry

Accurate ab-inito quantum mechanical calculations of pyrrole dimers are reported. The thermodynamical stabilities of dimers with $\alpha - \alpha, \alpha - \beta$, and $\beta - \beta$ type linkages are compared in order to predict the possibilities of branching in polypyrroles. Calculations employing large basis sets and including electron correlation effects predict the $\alpha - \alpha$ dimers as the most stable form. However, an $\alpha - \beta$ type bonding requires only 1.5-2.0 kcal/mol, and the energy necessary to introduce a $\beta - \beta$ type bond is 3.6-4.0 kcal/mol. These values show that a high degree of branching is possible even at …

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Electrocatalytic Properties Of Platinum Doped Polyaniline And Polypyrrole Electrodes, F. Kadirgan, F. Fiçicioğlu, İ. Beceri̇k Jan 1998

Electrocatalytic Properties Of Platinum Doped Polyaniline And Polypyrrole Electrodes, F. Kadirgan, F. Fiçicioğlu, İ. Beceri̇k

Turkish Journal of Chemistry

This review paper aims to show how the electrochemical behaviour of polyaniline (PANI) and polypyrrole (PPy) electrodes modified by platinum help to improve the oxidation of organic molecules such as methanol, ethylene glycol and glucose. Although the amount of platinum deposited was very small, i.e., 0.1 mg.cm$^{-2}$, the catalytic activity obtained was comparable to bulk platinum. Another notable point is the reduction of the poisoning effect, which is the main problem faced in the electrooxidation of organic molecules for fuel cell applications.

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Cover And Contents Jan 1998

Cover And Contents

Turkish Journal of Chemistry

No abstract provided.

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Heat Treatment Of Maceral Groups Obtained From Turkish Bituminous Coals, Elif Sultan Vayi̇soğlu, Nevin Gaye Erbatur Jan 1998

Heat Treatment Of Maceral Groups Obtained From Turkish Bituminous Coals, Elif Sultan Vayi̇soğlu, Nevin Gaye Erbatur

Turkish Journal of Chemistry

The dilatation properties of parent coals and their maceral fractions were examined. In all the coal samples, the main petrographic constituent was the vitrinite maceral. Reflectance of the vitrinite and inertinite macerals increased after carbonization, while the liptinite maceral disappeared and caused large pores in the vitrinite macerals. All of the coals developed anisotropic coke.

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Heme Transfer Reactions: An Important Prerequisite For Synthetic Oxygen Carriers, Jan Paul, Wenhua Chen, Per-Ingvar Ohlsson, Michael Smith Jan 1998

Heme Transfer Reactions: An Important Prerequisite For Synthetic Oxygen Carriers, Jan Paul, Wenhua Chen, Per-Ingvar Ohlsson, Michael Smith

Turkish Journal of Chemistry

Electronic changes of iron- and metal free porphyrins are reviewed in light of their importance to modify the ferri/ferro reduction potential and energy dissipation between ligated carbon monoxide and the porphyrin chelate. Substitutions at positions 2 and 4 are effective ways to exercise this influence. Other measures include exposure to water and modifications of axial ligation, including the \lq three-ligand' case. These measures will also influence the stability of recombined hemin-protein entities, as apparent from the kinetics of heme-transfer from a modified donor protein to apomyoglobin, but the stability appears to be related to the bulkiness of 2,4-substitutional groups rather …

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Some Recursive Relationships Between Acenes And Cyclacenes, Lemi Türker Jan 1998

Some Recursive Relationships Between Acenes And Cyclacenes, Lemi Türker

Turkish Journal of Chemistry

Some structural relationships between acenes and cyclacenes both H\\"{u}ckel- and Mobius-type and within the same class of compounds were demonstrated by the recursive analysis of their $E_{\pi}$ and $I_{\pi}$ values or the first differences thereof. It was found that the first differences of $E_{\pi}$ and $I_{\pi}$ tend to have certain limit values as the number of benzenoid rings increases in each class of compounds studied.

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Thermodynamic Studies Of Some Complexes Of 2-Benzoylpyridine 4-Phenyl-3-Thiosemicarbazone, T. Atalay, E. Güler Akgemci̇ Jan 1998

Thermodynamic Studies Of Some Complexes Of 2-Benzoylpyridine 4-Phenyl-3-Thiosemicarbazone, T. Atalay, E. Güler Akgemci̇

Turkish Journal of Chemistry

The stability constants of the Co(II), Ni(II), Cu(II) and Zn(II) complexes with 2-benzoylpyridine 4-phenyl-3-thiosemicarbazone were determined using a spectrophotometric method at different temperatures (25, 30, 35 and 40 $\pm$ 0.1^oC) and ionic strengths (0.05, 0.01 and 0.20 M KNO$_3$) in 50 \% (v/v) aqueous ethanol. Plots of thermodynamic stability constants at zero ionic strength ($\ln$ K^o) versus T$^{-1}$ gave linear curves and $\Delta$ H^o and $\Delta$ S^o were also calculated from these plots. Moreover, the changes in free energy for each metal-ligand system were calculated from the following equation. $\Delta$ G^o = -RT $\ln$ K^o.

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The Removal Of Organic Sulfur From Two Turkish Lignites By Chlorinolysis, Yücel Y. Kadioğlu, Semra Karaca, Samih Bayrakçeken, M. Şahin Gülaboğlu Jan 1998

The Removal Of Organic Sulfur From Two Turkish Lignites By Chlorinolysis, Yücel Y. Kadioğlu, Semra Karaca, Samih Bayrakçeken, M. Şahin Gülaboğlu

Turkish Journal of Chemistry

The removal of organic sulfur from two Turkish lignites by chlorinolysis with chlorine gas in water and water-carbon tetrachloride media at ambient pressure was examined. The effects of stirring speed (5-20 s^{-1}), particle size (250-425, 150-180 and 74-88 \mu m), temperature (13-70°C) and time (0-10800 s) were investigated. Significant portions of the organic sulfur in the coal samples were removed.

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