Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- 1 (98)
- 2 (83)
- Synthesis (61)
- Adsorption (55)
- Antimicrobial activity (47)
-
- 3 (45)
- Phthalocyanine (35)
- Antibacterial activity (33)
- Molecular docking (30)
- Cytotoxicity (29)
- Preconcentration (26)
- Cyclic voltammetry (25)
- Palladium (25)
- Voltammetry (25)
- Schiff base (24)
- Spectrophotometry (24)
- Copper (23)
- Fluorescence (23)
- Lamiaceae (22)
- Antioxidant activity (20)
- DFT (20)
- Kinetics (20)
- Antioxidant (18)
- Cadmium (18)
- Catalyst (18)
- Chitosan (18)
- Nanoparticles (18)
- Photocatalysis (18)
- Antimicrobial (17)
- Electrospinning (16)
- Publication Year
Articles 2551 - 2580 of 2730
Full-Text Articles in Physical Sciences and Mathematics
Electrochemical Reduction Of Methyl Cinnamate In The Presence Of 1,3-Bis(4-Methyl Phenylsulphonyloxy)Propane, Mustafa Güllü
Electrochemical Reduction Of Methyl Cinnamate In The Presence Of 1,3-Bis(4-Methyl Phenylsulphonyloxy)Propane, Mustafa Güllü
Turkish Journal of Chemistry
Electrochemical reduction of methyl cinnamate in the presence of a dielectrophile, such as 1,3-bis(4-methyl phenylsulphonyloxy)propane gives two major products: trans- (\pm) methyl 2-phenylcyclopentanecarboxylate and trans- (\pm) methyl 2,3-diphenyl-5-oxo-cyclopentanecarboxylate. The ratio of products basically depends on the electrolysis conditions.
Comparative Mechanistic Studies On The Oxidation Of Aromatic And Aliphatic Hydroxyl Derivatives In An Alkaline Medium At Preanodized Pt, Au And Pt/Au Electrodes In Presence Of Redox Mediators, Sasha Kalcheva, Philip Iotov
Comparative Mechanistic Studies On The Oxidation Of Aromatic And Aliphatic Hydroxyl Derivatives In An Alkaline Medium At Preanodized Pt, Au And Pt/Au Electrodes In Presence Of Redox Mediators, Sasha Kalcheva, Philip Iotov
Turkish Journal of Chemistry
The role of redox mediators obtained from Pt, Au, and Pt/Au electrodes in the process of electrocatalytic oxidation of aromatic/aliphatic hydroxyl derivatives in an alkaline medium has been studied by applying cyclic voltammetry. Phenol and glycerol were used as aromatic and aliphatic hydroxyl derivatives in the electrochemical oxidation experiments. The results revealed that the presence of redox mediators formed by preliminary electrode anodization is crucial for the process of oxidation of aromatic compounds and imposes a different oxidation route for the aliphatic hydroxyl derivatives. The effect of preanodization has been related to the formation and dissolution of the corresponding higher …
Electrochemical Characterization Of Al_2 O_3 -Ni Thin Film Selective Surface On Aluminium, Fi̇gen Kadirgan, Ewa Wackelgard, Mete Söhmen
Electrochemical Characterization Of Al_2 O_3 -Ni Thin Film Selective Surface On Aluminium, Fi̇gen Kadirgan, Ewa Wackelgard, Mete Söhmen
Turkish Journal of Chemistry
Solar thermal collectors represent a widely used type of system for the conversion of solar energy. In order to produce selective coatings on aluminium substrates to be used as absorber plates in high efficiency solar collectors, nickel pigmentation was applied to anodically oxidised surfaces. Electrochemical dc methods are used to study the oxidation of aluminium as functions of the following electrolysis conditions: applied current, pH, temperature and concentration of electrolyte. The properties of the oxidised aluminium surfaces are investigated by cyclic voltammetry. Nickel pigmentation of porous aluminium surfaces was also performed as a function of electrochemical pigmentation conditions by ac …
The Effects Of Detergent Pollution On The Corrosion Of Iron And Aluminium, Si̇bel Zor, B. Yazici, M. Erbi̇l
The Effects Of Detergent Pollution On The Corrosion Of Iron And Aluminium, Si̇bel Zor, B. Yazici, M. Erbi̇l
Turkish Journal of Chemistry
The current-potential values were measured with iron or aluminium electrodes in solutions of 3.5% NaCl containing 30, 150, 300 ppm linear alkylbenzene (LAB) and detergents (LAS) at pH8. Polarization resistances (Rp) were determined using the values of current and potentials. The corrosion rates of iron and aluminium were determined in 2 and 4 hour intervals using the Mansfeld-Oldham equation based on the Stern-Geary and Butler-Volmer equations.
Reactions Of N-Aminopyrimidine Derivatives With 1,3-Dicarbonyl Compounds, Zülbi̇ye Önal, Behzat Altural
Reactions Of N-Aminopyrimidine Derivatives With 1,3-Dicarbonyl Compounds, Zülbi̇ye Önal, Behzat Altural
Turkish Journal of Chemistry
The reactions of 1-Amino-pyrimidine derivatives (1) and some 1,3-dicarbonyl compounds (2) were realized in the presence of p-toluensulfonic acid catalyst to give convenient enamine (3) and/or imine derivatives (4). In the same way, the enamine (5) and/or imine derivatives (6) were synthesized using (1) and 1,3-indanedione which is one of the different 1,3-dicarbonyl compounds. The molecular structures of all the prepared compounds were determined by ^1H-nmr, ^{13}C-nmr, i.r. spectra and elemental analyses, and were drawn by taking imine-enamine tautomerism into account.
Autocatalytic Reduction Of Dichloro 5, 10, 15, 20 Tetraphenylporphinatoplatinum(Iv) By 1-Methylimidazole, F. Ece Bulak
Autocatalytic Reduction Of Dichloro 5, 10, 15, 20 Tetraphenylporphinatoplatinum(Iv) By 1-Methylimidazole, F. Ece Bulak
Turkish Journal of Chemistry
It was observed that in toluene solution, excess 1-methyl-imidazole (Melm) reduces dichloro 5, 10, 15, 20 tetraphenyl-porphinatoplatinum(IV) (PtTPPCl_2) to tetraphenylporphinato-platinum(II) (PtTPP) autocatalytically (Fig. 1). There was no Pt(III) intermediate or 1-methylimidazole radical detected by Electron Resonance Spectroscopy (ESR) at 25°C. The reaction was found to be autocatalyzed by the PtTPP product when the 1-methylimidazole to PtTPPCl_2 concentration ratio is about 10^4 or more. From the data obtained it is reasonable to suppose that aggregation of the PtTPP product with PtTPPCl_2 plays an important role in this reduction process.
A Modified Potentiometric Method For The Estimation Of Phenol In Aqueous Systems, Farhat Huma, Muhammad Jaffar, Khalid Masud
A Modified Potentiometric Method For The Estimation Of Phenol In Aqueous Systems, Farhat Huma, Muhammad Jaffar, Khalid Masud
Turkish Journal of Chemistry
A modified potentiometric titration is proposed for the estimation of phenol in aqueous systems. The method is evolved on the basis of a critical dependence of pH on log V rather than simple V, as used in conventional potentiometric titrations. The method incorporates titrants in a concentration range several orders of magnitude greater than that of phenol in the aqueous phase. Derivative potentiometric curves so obtained provide a clear exposition of the equivalence point and the overall error is found to be between \pm 1.0 and 1.5%. The range of phenol concentration investigated was from 10^{-2} to 10^{-3} M. and …
Electrochemical Behaviour Of Hexa[4-(Phenylazo) Phenoxy]Cyclotriphasphazene, Necati̇ Menek, Günseli̇ Turgut, Mustafa Odabaşioğlu
Electrochemical Behaviour Of Hexa[4-(Phenylazo) Phenoxy]Cyclotriphasphazene, Necati̇ Menek, Günseli̇ Turgut, Mustafa Odabaşioğlu
Turkish Journal of Chemistry
The polarographic and voltammetric behaviour of hexa[4-(phenylazo)phenoxy]cyclotriphasphazene in tetrahydrofuran-water 50% (v/v) was studied at room temperature using various electrochemical techniques. In this study, the reduction of the azo group to the amino group of the organophosphazenes compound was observed as the electrode reaction. An electrode reaction mechanism was suggested for the compound.
Synthesis, Structural And Thermal Studies Of Titanium(Iv) Complexes Of N-Alkyl Phenothiazines, Jaldappa Seetharamappa, Boregowda Keshavan
Synthesis, Structural And Thermal Studies Of Titanium(Iv) Complexes Of N-Alkyl Phenothiazines, Jaldappa Seetharamappa, Boregowda Keshavan
Turkish Journal of Chemistry
New coordination compounds of the type [Ti(C_2O_4)_2L]2H_2O where L=N-alkyl phenothiazines (NAPs) were synthesised and characterised by elemental analyses, molar conductance, magnetic, thermal and spectral data. The spectral data suggest the bidentate nature of NAPs in the complexes. An octahedral structure is proposed for all the complexes. Thermal studies were used to evaluate the kinetic and thermodynamic parameters.
The Revovery Of Copper And Cobalt From Oxidized Copper Ore And Converter Slag, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari
The Revovery Of Copper And Cobalt From Oxidized Copper Ore And Converter Slag, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari
Turkish Journal of Chemistry
The aim of this study was to develop a method for obtaining copper and cobalt from oxidized copper ore and converter slag. In order to convert the copper and cobalt into sulfate compounds the main step was to roast the samples obtained by sulfurization and transfer the samples into solution. First the oxidized copper ore was roasted, followed by the mixture of converter slag and oxidized copper ore. Since the levels of copper and cobalt were low, the sulfurization process was carried out under autoclave conditions. The samples obtained were roasted. The yields of copper and cobalt passed into the …
Characterization Of An All-Optical Device Based On Organic Materials, Hans-Martin Keller, Mark Andreas Bader, Gerd Marowsky
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 …
Intrinsic Semiconducting Materials On Phthalocyanine Basis, Michael Hanack
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 …
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
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.
Azobenzene Side-Chain Liquid Crystalline Polyesters With Outstanding Optical Storage Properties, S. Hvilsted, M. Pedersen, N.C.R. Holme, P.S. Ramanujan
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 …
Electropolymerization Of Thiophene With And Without Aniline In Acetonitrile, Muzaffer Can, Kadir Pekmez, Nuran Pekmez, Attila Yildiz
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 …
Poly(3-Alkylthiophene) Modifications, A. Bolognesi
Poly(3-Alkylthiophene) Modifications, A. Bolognesi
Turkish Journal of Chemistry
No abstract provided.
Xps Investigations On Conducting Polymers, Ş. Süzer, Ö. Bi̇rer, U.A. Sevi̇l, O. Güven
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 …
Electrochromism Of Sol-Gel Derived Niobium Oxide Films, M. Maçek, B. Orel
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.
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
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.
Dc Conduction In Electrochemically Synthesized Polypyrrole Films, Akif Kaynak
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, …
Dimerization Of Pyrrole, Mine Yurtsever, Ersin Yurtsever
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 …
Electrocatalytic Properties Of Platinum Doped Polyaniline And Polypyrrole Electrodes, F. Kadirgan, F. Fiçicioğlu, İ. Beceri̇k
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.
Heat Treatment Of Maceral Groups Obtained From Turkish Bituminous Coals, Elif Sultan Vayi̇soğlu, Nevin Gaye Erbatur
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.
Heme Transfer Reactions: An Important Prerequisite For Synthetic Oxygen Carriers, Jan Paul, Wenhua Chen, Per-Ingvar Ohlsson, Michael Smith
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 …
Some Recursive Relationships Between Acenes And Cyclacenes, Lemi Türker
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.
The Amido And Bisalkoxo-Complexes Of [Tri(3,5-Dimethylpyrazolyl)Borato]Molydenum Nitrosyl, Işıl Topaloğlu
The Amido And Bisalkoxo-Complexes Of [Tri(3,5-Dimethylpyrazolyl)Borato]Molydenum Nitrosyl, Işıl Topaloğlu
Turkish Journal of Chemistry
In this study, the amido nitrosyl molybdenum complex, [Mo{HM(3,5-Me_2C_3HN_2)_3}(NO)Cl(NH_2)], was prepared. This compound reacts with alocohols, yielding the bisalkoxo complexes, [Mo{HM (3,5-Me_2C_3HN_2)_3}(NO)(OR)_{2}] (R = Me, Et, Pr^n, Bu^n). The new complexes were analyzed by IR and ^1H-NMR spectroscopy.
Thermodynamic Studies Of Some Complexes Of 2-Benzoylpyridine 4-Phenyl-3-Thiosemicarbazone, T. Atalay, E. Güler Akgemci̇
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.
The Removal Of Organic Sulfur From Two Turkish Lignites By Chlorinolysis, Yücel Y. Kadioğlu, Semra Karaca, Samih Bayrakçeken, M. Şahin Gülaboğlu
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.
Reaction Of 3,4-Diformyl-2,5-Dimethylpyrrole With 1,2(Substituted)Diphenyl-1,2-Diaminoethanes, Cemil Öğreti̇r, Fatma Severcan
Reaction Of 3,4-Diformyl-2,5-Dimethylpyrrole With 1,2(Substituted)Diphenyl-1,2-Diaminoethanes, Cemil Öğreti̇r, Fatma Severcan
Turkish Journal of Chemistry
3,4-Diformyl-2,5-dimethylpyrrole (1) reacts with 1,2-diphenyl-1,2-diamine derivatives to form the potentially tautomeric 2:2 macrocyclic adduct (1)=(1). ^1H and ^{13}C n.m.r. spectral data along with acidity measurements indicate that the 2-azafulvene structure (7) is predominant for all adducts.
The Adsorption Isotherms Of The Bleaching Of Sun Ower-Seed Oil, Hüseyin Topallar
The Adsorption Isotherms Of The Bleaching Of Sun Ower-Seed Oil, Hüseyin Topallar
Turkish Journal of Chemistry
In this study, the absorbance measurements were taken for the bleaching of sunflower-seed oil with wt. 0.3, 0.5, 0.7 and 0.9 % of clay at 60, 70, 80 and 90°C. Bentonite EY-09 was used as the bleaching clay. Since the heat evolved during adsorption (0.33-1.07 kJ mol^{-1}) was less than 20 kJ mol^{-1}, the forces between the adsorbent and adsorbate appear to be van der Waals forces, and this type of adsorption is physical or van der Waals adsorption. Thus, it was seen that the Freundlich equation was more applicable than the Langmuir equation to the experimental adsorption isotherms for …