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2001

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Articles 2911 - 2940 of 3067

Full-Text Articles in Physical Sciences and Mathematics

Spatial Distribution Of Phosphorus In Fluvial Sediments From The James River Basin, Sw Missouri, Briain Fredrick Jan 2001

Spatial Distribution Of Phosphorus In Fluvial Sediments From The James River Basin, Sw Missouri, Briain Fredrick

MSU Graduate Theses

Degraded ·water quality in the James River Arm of Table Rock Lake, southwest Missouri has raised concerns about sources and transport of nutrients, especially phosphorus, in the James River Basin. Sections of the James River Basin have been identified as having excessive nutrient problems on the Missouri Department of Natural Resources 303d list and ranked fifth in the state for water quality improvements. Understanding the sources and transport patterns of phosphorus in the James River is necessary to evaluate contamination problems and the effectiveness of management efforts to reduce phosphorus inputs to the lake. This study uses bed sediments to …


Spatial Patterns And Floodplain Contributions Of Mining-Related Contaminants In Chat Creek Watershed, Southwest Missouri, Jimmy Trimble Jan 2001

Spatial Patterns And Floodplain Contributions Of Mining-Related Contaminants In Chat Creek Watershed, Southwest Missouri, Jimmy Trimble

MSU Graduate Theses

Past mining activities have left a legacy of water quality problems in the Tri-State Mining District. Contemporary environmental risks stem from the release of lead and zinc from mine tailings previously dispersed far downstream in alluvial deposits as well as abandoned tailings piles. This study examines mining-related heavy metal contamination in the Chat Creek Watershed. Chat Creek drains the area near Aurora, Missouri on the eastern edge of the Tri-State District where mining occurred from 1886 to about 1930. This study identifies the spatial distribution of metal contamination in fluvial sediments and quantifies the role of bank erosion as a …


Soilguide (Soil Guide) : A Handbook For Understanding And Managing Agricultural Soils, Geoff Allan Moore Jan 2001

Soilguide (Soil Guide) : A Handbook For Understanding And Managing Agricultural Soils, Geoff Allan Moore

Bulletins 4000 -

This handbook integrates the current knowledge of soils in south-western Australia in a user-friendly form. It describes how to assess which soil properties influence production and land degradation in the agricultural area and summarises management options to remedy or minimise soil limitations. The potential for growing a large range of crops and pastures can be assessed. In particular, the links between soil morphology, soil properties, management and agronomy are emphasised. The manual is designed for use at the paddock scale or for site assessment, but it can also be used at a catchment or regional scale. It is specifically designed …


Soil Factors Influencing Eutrophication. In Soilguide. A Handbook For Understanding And Managing Agricultural Soils. (Ed. Geoff Moore), David Weaver, Robert Summers Jan 2001

Soil Factors Influencing Eutrophication. In Soilguide. A Handbook For Understanding And Managing Agricultural Soils. (Ed. Geoff Moore), David Weaver, Robert Summers

Bulletins 4000 -

Eutrophication is essentially the nutrient enrichment of waterways leading to algal growth. It must be controlled to maintain sustainable agricultural systems and the main mechanisms of control are stabilising catchment processes and reducing nutrient output.

Eutrophication can be defined as 'the nutrient enrichment of waters which results in the stimulation of an array of symptomatic changes, among which increased production of algae and macrophytes, deterioration of water quality and other symptomatic changes, are found to be undesirable and interfere with water uses' (OECD 1982). The word eutrophic is a Greek word that means 'well fed'. The food referred to is …


Before And After Riparian Management: Sediment And Nutrient Exports From A Small Agricultural Catchment, Western Australia, Lucy Mckergow, David Weaver, I Prosser, R Grayson, A. E.G. Reed Jan 2001

Before And After Riparian Management: Sediment And Nutrient Exports From A Small Agricultural Catchment, Western Australia, Lucy Mckergow, David Weaver, I Prosser, R Grayson, A. E.G. Reed

Conference papers and presentations

Riparian vegetation can trap sediment and nutrients coming from hillslopes and reduce stream bank erosion. This study presents results from a 10 year stream monitoring program in a small agricultural catchment near Albany, Western Australia. In 1996, a 1.6 km stream reach was fenced, planted with eucalyptus species and managed separately from the adjacent paddocks. Stream flow, nutrient and sediment concentration data were collected at the downstream end of the fenced riparian area between 1991 and 2000, so there are data for the “before” and “after” riparian management periods. Suspended sediment concentrations fell dramatically following riparian management; the average event …


Preparation And Characterization Of Molecular Imprinting Polymer With (S)-Naproxen, Yue Hu Jan 2001

Preparation And Characterization Of Molecular Imprinting Polymer With (S)-Naproxen, Yue Hu

Dissertations, Theses, and Masters Projects

No abstract provided.


The Synthesis And Characterization Of Cu(I) Networks With Heterocyclic Bridging Ligands, Jonathan Timothy Maeyer Jan 2001

The Synthesis And Characterization Of Cu(I) Networks With Heterocyclic Bridging Ligands, Jonathan Timothy Maeyer

Dissertations, Theses, and Masters Projects

No abstract provided.


Evaluation Of In Situ Bioremediation Approaches In Meeting International Standards For Organic And Residual Metals Toxicity In Soils, Jason Allan Mcdonald Jan 2001

Evaluation Of In Situ Bioremediation Approaches In Meeting International Standards For Organic And Residual Metals Toxicity In Soils, Jason Allan Mcdonald

LSU Master's Theses

Drilling fluids and muds are an essential component of the rotary drilling process used to drill for oil and gas on land and in offshore environments. However, the bioaccumulation of petroleum contaminated soils/drilling mud due to oil and natural gas exploration has posed a major environmental concern due to its prolonged environmental persistence and its leachability below the rhizosphere. The main objectives of this research were: (i) To assess initial toxicity of drilling mud and related contaminated soils from an agricultural setting in Galliano, Sicily (Phase one) and (ii) To develop a low intervention bioremediation approach using bioplug technology to …


Relationships Between Stream Order And Management Priority: A Water Quality Case Study, David Weaver, Adrian Reed, John Grant Jan 2001

Relationships Between Stream Order And Management Priority: A Water Quality Case Study, David Weaver, Adrian Reed, John Grant

Conference papers and presentations

Seagrass, which once dominated the habitat of Oyster Harbour on the south coast of Western Australia has been replaced by macroalgae because of increased nutrient and sediment discharge from the rural dominated catchment. Total Phosphorus (TP), Total Nitrogen (TN), Suspended Sediment (SS) and Electrical Conductivity (EC) concentrations from a catchment – wide (168 sites), event-driven snapshot, water quality monitoring program conducted from 1994 to 1996, were analysed in relation to stream order and published survey data on riparian zone condition. This analysis was performed to examine relationships between stream order, riparian zone condition and water quality, and implications for the …


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 Jan 2001

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 …


Selenium Speciation In Karakaya Dam Lake's Water (Malatya-Turkey), F. Zehra Küçükbay, Mustafa Demi̇r Jan 2001

Selenium Speciation In Karakaya Dam Lake's Water (Malatya-Turkey), F. Zehra Küçükbay, Mustafa Demi̇r

Turkish Journal of Chemistry

Concentrations of total inorganic selenium, Se(IV), Se(VI) and organically bonded selenium from samples of Karakaya dam lake\\\'s water were determined using ammonium pyrollidine dithio carbamate (APDC) as a chelating agent and subsequent adsorption on amberlite type XAD-8 resins. Eluted analytes are taken up in a matrix free acidic solution suitable for graphite furnace atomic absorption spectroscopy (GFAAS). According to our results, levels of the total inorganic selenium, Se(IV), Se(VI) and organically bonded selenium were found to be between 0.11 \\pm 0.01 and 0.17 \\pm 0.01 \\mug/L, 0.07 \\pm 0.01 and 0.12 \\pm 0.01 \\mug/L, 0.02 \\pm 0.01 and 0.05 \\pm …


Longshore Sediment Transport As A Function Of Energy Dissipation, Ernest R. Smith, Ping Wang Jan 2001

Longshore Sediment Transport As A Function Of Energy Dissipation, Ernest R. Smith, Ping Wang

Geology Faculty Publications

Experiments to measure waves, currents, and sediment transport rate for two breaker types, plunging and spilling, were conducted in a large-scale three-dimensional physical model. It was found that there was a large difference in cross-shore distribution and total sediment transport rate between the two breaker types. Total transport rates compared to existing predictive equations. The equations generally did not predict the data well. With the exception of the Kamphuis (1991) equation, which included a dependence on wave period, the predictive equations did not differentiate between breaker types.


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 Jan 2001

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 The Thermodynamic Properties Of Poly [2-(3-Phenyl-3-Methylcyclobutyl)-2-Hydroxyethyl Methacrylate-Co-Methacrylic Acid] At Infinite Dilution By Inverse Gas Chromatography, İsmet Kaya, Kadi̇r Demi̇relli̇ Jan 2001

Determination Of The Thermodynamic Properties Of Poly [2-(3-Phenyl-3-Methylcyclobutyl)-2-Hydroxyethyl Methacrylate-Co-Methacrylic Acid] At Infinite Dilution By Inverse Gas Chromatography, İsmet Kaya, Kadi̇r Demi̇relli̇

Turkish Journal of Chemistry

Some thermodynamic quantities were obtained for the interactions of poly [2-(3-phenyl -3- methylcyclobutyl)-2-hydroxyethyl methacrylate-co-methacrylic acid] Poly (PCHEMA-co-MA) with alcohols, ketones, acetates, aromatics and n-alkanes by inverse gas chromatography in the temperature range of 150-180^oC. The specific retention volumes, Vg^o, weight fraction activity coefficients of solute probes at infinite dilution, \Omega_{1}^{\infty} and Flory-Huggins thermodynamic interaction parameters, \chi_{12}^{\infty} between polymers and solvents were determined. The partial molar free energy, \DeltaG_{1}^{\infty} , the partial molar heat of mixing, \DeltaH_{1}^{\infty} , at infinite dilution and the solubility parameters of the polymer, \delta_{2} , were calculated. The copolymer was characterized by ^1 H-NMR, FT-IR and …


Electrorheological Properties Of Suspensions Prepared From Polystyrene- Block- Polyisoprene Copolymer, Hali̇l İbrahi̇m Ünal, Yilmaz Yildirir, Mustafa Yavuz Jan 2001

Electrorheological Properties Of Suspensions Prepared From Polystyrene- Block- Polyisoprene Copolymer, Hali̇l İbrahi̇m Ünal, Yilmaz Yildirir, Mustafa Yavuz

Turkish Journal of Chemistry

Considerable scientific and industrial interest is currently being focused on a class of materials known as electrorheological (ER) fluids, which display remarkable rheological behaviour, being able to convert rapidly and repeatedly from a liquid to solid when an electric field (E) is applied or removed. In this article, the synthesis, characterization, partial hydrolysis and ER properties of polystyrene- block}-polyisoprene copolymer (COP) were investigated. The block copolymer was characterized by GPC, viscosity measurements, ^1 H-NMR and FTIR spectroscopies, particle size measurements, and elemental analysis. The polystyrene block of the copolymer was partially hydrolyzed by a series of chemical reactions and then …


Voltammetric And Polarographic Studies Of Eriochrome Black T - Nickel(Ii) Complex, Osman Çakir, Emi̇ne Ertürk Coşkun, Ender Bi̇çer, Semi̇ha Çakir Jan 2001

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.


The Sorption Of Metals On The Polysulfone Cation Exchange Membranes, Mustafa Ersöz, İlkay Hi̇lal Güğül, Aysel Çi̇men, Betül Leylek, Sali̇h Yildiz Jan 2001

The Sorption Of Metals On The Polysulfone Cation Exchange Membranes, Mustafa Ersöz, İlkay Hi̇lal Güğül, Aysel Çi̇men, Betül Leylek, Sali̇h Yildiz

Turkish Journal of Chemistry

The sorption of NaCl and CaCl_2 and monovalent-divalent cation salt mixtures on the polysulfone and polysulfone with polyester support cation exchange membranes were investigated. The sorption of monovalent-divalent cation salt mixtures in contact with NaCl+CaCl_2 salt mixtures were studied at a total concentration of 0.05 M. The obtained results for polysulfone type membranes were compared with Neosepta CL-25T and CM2 cation exchange membranes.


Determination Of Hydrochlorothiazide And Enalapril Maleate In Tablet Formulations By Reversed-Phase Hplc, Idrees F. Al-Momani̇ Jan 2001

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.


A Comparative Study On The Recovery Of Ecori Endonuclease From Two Different Genetically Modified Strains Of Escherichia Coli, Candan Tamerler, Zeynep İlsen Önsan, Betül Kirdar Jan 2001

A Comparative Study On The Recovery Of Ecori Endonuclease From Two Different Genetically Modified Strains Of Escherichia Coli, Candan Tamerler, Zeynep İlsen Önsan, Betül Kirdar

Turkish Journal of Chemistry

A laboratory scale procedure developed for the purification of EcoRI restriction endonuclease was applied to two different Escherichia coli} strains, E. coli 294 and E. coli M5248, which are genetically modified to overproduce the enzyme. The purification method consisted of three successive chromatographic steps including phosphocellulose and hydroxyapatite columns and further fractionation in a second phosphocellulose column. It was shown that the second phosphocellulose separation can be omitted in the case of E. coli 294. Quality control tests indicated enzyme preparations free of contaminants and endo- or exo-nucleases. The yields obtained at the final stage of the purification were 1.3x10^{5} …


Studies On The Thermal Decomposition Of Copper (Ii) Flouride Complexes With Various Amino Acids In Nitrogen Atmosphere, Muhammad Arif, Saeed-Ur Rehman, Muhammad Arshad, Khalid Masud, Nasima Arshad Jan 2001

Studies On The Thermal Decomposition Of Copper (Ii) Flouride Complexes With Various Amino Acids In Nitrogen Atmosphere, Muhammad Arif, Saeed-Ur Rehman, Muhammad Arshad, Khalid Masud, Nasima Arshad

Turkish Journal of Chemistry

Thermal decomposition reactions of various copper (II) fluoride complexes of the general type Cu (L) F.xH_2O (L= asparagine(asp), arginine (arg), methionine (meth) and proline (pro), x = 3 to 4) have been studied in nitrogen atmosphere using TG and DTA techniques. A possible mechanism of decomposition is suggested on the basis of the reactions of their pyrolysis. The residues obtained at the end of various decomposition processes were identified through IR spectrometry. The kinetic parameters such as energy of activation (E^o ) and order of reaction (n) were also determined.


Fluorimetric Detection Of Insulin In The Presence Of Eu(Iii) - {Pyridine - 2,6 - Dicarboxylate} Tris Complex, Elmas Gök, Serdar Ateş Jan 2001

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.


The Isolation Of Carboxylic Acids From The Flowers Of Delphinium Formosum, Nedi̇me Dürüst, Seçki̇n Özden, Esra Umur, Yaşar Dürüst, Mustafa Küçüki̇slamoğlu Jan 2001

The Isolation Of Carboxylic Acids From The Flowers Of Delphinium Formosum, Nedi̇me Dürüst, Seçki̇n Özden, Esra Umur, Yaşar Dürüst, Mustafa Küçüki̇slamoğlu

Turkish Journal of Chemistry

From the flowers of Delphinium formosum Boiss. et Huet. (Ranunculaceae) trans-aconitic, p-hydroxybenzoic, p-coumaric, caffeic and chlorogenic acids were isolated and identified. In addition, protocatechuic, vanillic and gentisic acids were identified.


Spectrophotometric Determination Of Cobalt, Nickel Palladium, Copper, Ruthenium And Molybdenum Using Sodium Isoamylxanthate In Presence Of Surfactants, Ashok Kumar Malik, K. N. Kaul, B. S. Lark, W. Faubel, A. L. J. Rao Jan 2001

Spectrophotometric Determination Of Cobalt, Nickel Palladium, Copper, Ruthenium And Molybdenum Using Sodium Isoamylxanthate In Presence Of Surfactants, Ashok Kumar Malik, K. N. Kaul, B. S. Lark, W. Faubel, A. L. J. Rao

Turkish Journal of Chemistry

A direct method has been developed for the spectrophotometric determination of microamounts of Co(II), Ni(II), Cu(II), Pd(II), Ru(III) and Mo(VI) using sodium isoamylxanthate as a reagent in the presence of surfactant as solubilising agent. The method has been applied to the determination of these metal ions in various alloys and in environmental samples (fly ash).


Unusual Chemical Constituents Of Lotus Garcinii (Fabaceae), Muhammad Shaiq Ali, Farman Ahmad, Viqar Uddin Ahmad, Iqbal Azhar, Khan Usmanghani Jan 2001

Unusual Chemical Constituents Of Lotus Garcinii (Fabaceae), Muhammad Shaiq Ali, Farman Ahmad, Viqar Uddin Ahmad, Iqbal Azhar, Khan Usmanghani

Turkish Journal of Chemistry

The methanol soluble part of Lotus garcinii, belonging to the family Fabaceae, yielded three new interesting metabolites: garceine (1), garoside (2) and garthiol (3), which have never been detected from any natural source. In addition, isophytol, hexadecanoic acid, cholesterol, oleanolic acid, butulinic acid and lupeol were also obtained for the first time from L. garcinii}. All the isolated metabolites were characterized by spectroscopic means.


Determination Of Fluoride And Some Metal Ion Levels In The Drinking Waters In Kayseri Province, Şeri̇fe Tokalioğlu, Uğur Şahi̇n, Şenol Kartal Jan 2001

Determination Of Fluoride And Some Metal Ion Levels In The Drinking Waters In Kayseri Province, Şeri̇fe Tokalioğlu, Uğur Şahi̇n, Şenol Kartal

Turkish Journal of Chemistry

Fluorine is one of the most common elements in the Earth's crust. Fluoride is recognized to be the most effective caries-preventive agent. The main sources of fluoride for people are generally food and drinking water. For this reason, the fluoride and also the metal ion (Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn) concentrations in the drinking waters collected from the city center of Kayseri and its counties were investigated. In the determination of fluoride and of Na and K, an ion-meter with a combination-fluoride electrode and a flame photometer were used, respectively. The levels of …


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 Jan 2001

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.


Cross-Correlation Noise Studies In Atomic Magnet-Optic Rotation Spectroscopy, Ahmet T. İnce Jan 2001

Cross-Correlation Noise Studies In Atomic Magnet-Optic Rotation Spectroscopy, Ahmet T. İnce

Turkish Journal of Chemistry

Analytical signals in an Atomic Magneto-Optic Rotation spectrometer are buried in noise at the limit of detection. The noisy analytical signals were analysed by carrying out mathematical correlation of their time domain waveforms. The noise components of signals were removed by auto-correlation to simplify the study. If noise interferes in analytical signals whose source is unclear, a cross-correlation of the output waveform with noise source may identify the source, e.g., mains frequencies and background radio signals. A cross-correlation will reveal whether the two signals are derived from the same source. This can also lead to an improvement in the signal …


Simultaneous Determination Of Inorganic Anions And Organic Acids By Capillary Electrophoresis, Nevi̇n Özteki̇n, F. Bedi̇a Eri̇m Berker Jan 2001

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 …


Analysis Of Polychlorinated Dibenzofurans (Pcdfs) Isomers In Soil Samples, Mustafa Pehli̇van, Erol Pehli̇van Jan 2001

Analysis Of Polychlorinated Dibenzofurans (Pcdfs) Isomers In Soil Samples, Mustafa Pehli̇van, Erol Pehli̇van

Turkish Journal of Chemistry

This study presents an analytical method for the separation of a series of polychlorinated dibenzofurans (PCDFs) emitted to the soil. PCDF contaminants were concentrated from soil samples and isolated from other materials by chromatographic methods and their quantitative determinations were performed by GC/MS (gas chromatography/mass spectroscopy).


Usefulness Of A Technique Based On Negative Corona Discharge For The Degradation Of Selected, Condensed Pahs: Application To The Oxidation Of Anthracene And Similar Structures, D. Tessi̇er, C. Oguic, J. Pinart, J. J. Aaron Jan 2001

Usefulness Of A Technique Based On Negative Corona Discharge For The Degradation Of Selected, Condensed Pahs: Application To The Oxidation Of Anthracene And Similar Structures, D. Tessi̇er, C. Oguic, J. Pinart, J. J. Aaron

Turkish Journal of Chemistry

The usefulness of negative corona discharge for oxidation of condensed polycyclic aromatic hydrocarbons (PAHs), including anthracene, naphthalene and 2,3-benzanthracene, adsorbed on a solid substrate is evaluated. In the case of anthracene, the application of corona discharge under high voltage (10-20 kV) for 10 to 180 min with a current intensity of 5-120 \mu A in a controlled, humid atmosphere leads to the progressive formation of anthraquinone. A kinetic study of the anthracene oxidation shows that the apparent half-lives range from 5 to 48 min, according to the initial anthracene amount (50-5000 nmol), indicating a reaction order between 0 and 1. …