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2017

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Articles 23821 - 23850 of 24647

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Diastereoselective Synthesis Of Novel 2,5-Dioxopyrrolidine Derivatives Via Biocatalytic Domino Reactions, Saadieh Mohajer, Robabeh Baharfar Jan 2017

Diastereoselective Synthesis Of Novel 2,5-Dioxopyrrolidine Derivatives Via Biocatalytic Domino Reactions, Saadieh Mohajer, Robabeh Baharfar

Turkish Journal of Chemistry

A series of novel 2,5-dioxopyrrolidines were synthesized by the one-pot reaction of coumarin-3-carboxylic acids 1 with thiourea derivatives and alkyl isocyanides in the presence of Fe$_{3}$O$_{4}$ NPs @ lipase as heterogeneous reusable nanobiocatalysts with high yields.

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Synchrotron X-Ray Diffraction Studies Of $\Beta $-Ca$_{2-X}M_{X}$Sio$_{4}$ ($M$ = Mg And Sr), Anti Prodjosantoso, Brendan Kennedy Jan 2017

Synchrotron X-Ray Diffraction Studies Of $\Beta $-Ca$_{2-X}M_{X}$Sio$_{4}$ ($M$ = Mg And Sr), Anti Prodjosantoso, Brendan Kennedy

Turkish Journal of Chemistry

The structures of Mg- and Sr-doped $\beta $-Ca$_{2}$SiO$_{4}$ have been established from high-resolution synchrotron X-ray powder diffraction. These silicates are all isostructural and the structures have been refined in the monoclinic space group, $P$2$_{1}$/$n$. As expected based on size arguments, the cell parameters increase as the amount of Sr increases and likewise decrease as the amount of Mg increases due the size effects of the dopant cation. In all cases the SiO$_{4}$ tetrahedra are essentially regular.

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Ultrasonic Activation Of The Arylation Reaction Of Styrene Catalyzed By Transition Metals, Dhiab Atoui, Khemais Said, Ridha Ben Salem Jan 2017

Ultrasonic Activation Of The Arylation Reaction Of Styrene Catalyzed By Transition Metals, Dhiab Atoui, Khemais Said, Ridha Ben Salem

Turkish Journal of Chemistry

The arylation reaction of styrene was tested in the presence of different transition metal-based catalysts, mainly iron-based, given its low cost and its nonpolluting and nontoxic characteristics. The study of the effect of sonochemical activation on the evolution of the selectivity of the reaction is also proposed. Higher efficiency was observed for a very short period of time of just a few minutes. Furthermore, an improvement of the selectivity of the arylation of the external carbon of styrene was observed.

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Online Coupling Electrochemical Preconcentration And Gfaas Technique As Effective Method For Determination Of Ultratrace Concentrations Of Antimony In Groundwater And Surface Water Samples, Lubomir Machynak, Martin Nemecek, Ernest Beinrohr, Frantisek Cacho Jan 2017

Online Coupling Electrochemical Preconcentration And Gfaas Technique As Effective Method For Determination Of Ultratrace Concentrations Of Antimony In Groundwater And Surface Water Samples, Lubomir Machynak, Martin Nemecek, Ernest Beinrohr, Frantisek Cacho

Turkish Journal of Chemistry

The present article describes a method of determination of low antimony concentrations using a graphite furnace AAS technique after electrochemical preconcentration. A 2-electrode flow-through cell was developed with a working electrode made of gold-coated porous carbon and an accessory Pt electrode. This cell worked in online coupling with the graphite furnace atomizer. Accumulation occurred from the 6 M hydrochloric acid solution and 2 M nitric acid was used to dissolve and transport antimony into the sampling loop. The sampling loop was placed on a 6-way valve. The preconcentrated solution was transported to the atomizer using an air jet. The detection …

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Achieving Elusive Transformations With Organocatalysis: Direct $\Beta $-Carbon Activation Of Saturated Carbonyl Compounds, Rafik Rajjak Shaikh Jan 2017

Achieving Elusive Transformations With Organocatalysis: Direct $\Beta $-Carbon Activation Of Saturated Carbonyl Compounds, Rafik Rajjak Shaikh

Turkish Journal of Chemistry

Direct $\beta $-carbon activation of saturated carbonyl compounds for carrying out fast forward $\beta$-functionalization has been one of the most difficult to achieve tasks in catalysis. In the past few years, this challenging issue has attracted considerable attention among the chemical community that has led to fruitful developments to accomplish this elusive transformation. In this short review, we highlight recent developments for direct $\beta $-carbon functionalization of saturated carbonyl compounds based on conceptually new methods including oxidative enamine catalysis, $N$-heterocyclic carbene (NHC)-assisted catalysis, and photoredox catalysis.

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Synthesis And Antinociceptive Activities Of Some Novel Benzimidazole-Piperidine Derivatives, Ümi̇de Demi̇r Özkay, Özgür Devri̇m Can, Nazli Turan, Betül Kaya Çavuşoğlu Jan 2017

Synthesis And Antinociceptive Activities Of Some Novel Benzimidazole-Piperidine Derivatives, Ümi̇de Demi̇r Özkay, Özgür Devri̇m Can, Nazli Turan, Betül Kaya Çavuşoğlu

Turkish Journal of Chemistry

In this study, a series of benzimidazole-piperidine derivatives were synthesized with the objective of developing potent antinociceptive agents. Some 2-(4-substituted-phenyl)-1-[2-(piperidin-1-yl)ethyl]-1$H$-benzimidazole derivatives were obtained by microwave-supported reaction of an appropriate 2-(4-substituted-phenyl)-1$H$-benzimidazole with 2-(piperidine-1-yl)ethyl chloride. The chemical structures of the compounds were elucidated by FT-IR, $^{1}$H NMR, $^{13}$C NMR, and HRMS spectral data. Antinociceptive activity was assessed by conducting hot-plate, paw-pressure, and formalin tests. Morphine (5 mg/kg, i.p) was used as a reference drug. Among the tested compounds 2a-2d and 2f-2h (10 mg/kg) increased the maximum possible effect (MPE) % values calculated for the hot-plate and paw-pressure tests and decreased the paw …

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Synthesis And Mao Inhibitory Activity Of Novel Thiazole-Hydrazones, Özlem Atli, Yusuf Özkay Jan 2017

Synthesis And Mao Inhibitory Activity Of Novel Thiazole-Hydrazones, Özlem Atli, Yusuf Özkay

Turkish Journal of Chemistry

A series of new thiazole-hydrazones 3a-3n were synthesized, characterized, and screened for their $h$MAO-A and $h$MAO-B inhibitory activity by an in vitro fluorometric method. Selectivity indexes (SIs) were expressed as IC$_{50}$ (MAO-A) / IC$_{50}$ (MAO-B). Compound 3f showed promising $h$MAO-A inhibition with an IC$_{50}$ value of 1.20 $\mu $M and displayed a very significant SI of 0.04 towards $h$MAO-A. The mechanism of $h$MAO-A inhibition was investigated by enzyme kinetics using Lineweaver--Burk graphics. Compound 3f was further screened for its cytotoxicity by using a healthy NIH/3T3 mouse embryonic fibroblast cell line (ATCC CRL1658) and was evaluated as nontoxic at its effective …

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A New Method For Simultaneous Determination Of Trace Amounts Of Cu(Ii) And Ni(Ii) Ions By Preconcentration And Spectrophotometric Analysis, Berri̇n Topuz, Şennur Merve Adanur, Arda Yalçuk Jan 2017

A New Method For Simultaneous Determination Of Trace Amounts Of Cu(Ii) And Ni(Ii) Ions By Preconcentration And Spectrophotometric Analysis, Berri̇n Topuz, Şennur Merve Adanur, Arda Yalçuk

Turkish Journal of Chemistry

Immediate preconcentration and spectrophotometric methods have been developed for the determination of trace amounts of cupric ion (Cu(II)) and nickel ion (Ni(II)) through a solid phase extraction with XAD-4-N,N'-bis-(salicylidene) cyclohexanediamine (XAD-4-SCHD) resin and a complex color reaction of the ions with 2,6-dimethyl-morpholine dithiocarbamate (DMMDTC) in Triton X-100 media. A high preconcentration factor of 125 was achieved. The spectrophotometric method was based on the measurements of the absorption of colored chelates of ions complexing with DMMDTC, and the adsorptions of the complex solutions were measured at their maximum absorption peaks at 460 and 328 nm for Cu(II) and Ni(II) ions, respectively. …

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Synthesis Of Phosphorus-Containing Polyurethanes And Poly(Urethane-Acrylate)S, Mahi̇r Burak Südemen, Hacer Ayşen Önen Jan 2017

Synthesis Of Phosphorus-Containing Polyurethanes And Poly(Urethane-Acrylate)S, Mahi̇r Burak Südemen, Hacer Ayşen Önen

Turkish Journal of Chemistry

Solvent-based polyurethanes and poly(urethane-acrylate)s were synthesized using phosphorus-containing polyester polyols in order to compare the thermal properties of different polymer types. Since the location of the phosphorus group might have vital importance when comparing the thermal properties, phosphorus groups were kept on the pendant chains in poly(urethane-acrylate)s using phosphorus-containing urethane macromonomers while they were kept on the backbone in polyurethanes. The effect of molar mass of polyurethanes and pendant urethane chains of poly(urethane-acrylate)s on thermal properties was also investigated. Characterization of the synthesized polymers was carried out using FT-IR, GPC, NMR, and DSC followed by evaluation of the thermal properties.

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Photoemissive Polymer Composite Based On New Y(Iii), Gd(Iii), And Tb(Iii) Complexes With N-Hydroxyphthalimide, Catalina Yarodara Rosca, Petronela Horlescu, Corneliu S.Stan, Daniel Sutiman Jan 2017

Photoemissive Polymer Composite Based On New Y(Iii), Gd(Iii), And Tb(Iii) Complexes With N-Hydroxyphthalimide, Catalina Yarodara Rosca, Petronela Horlescu, Corneliu S.Stan, Daniel Sutiman

Turkish Journal of Chemistry

In the present work, a green emitting composite with attractive photoluminescent properties was obtained through the embedding of the Tb$^{3+}$ complex with N-hydroxyphthalimide in a poly-(N-vinyl-pyrrolidone) matrix, which was further processed in thin or thick films. First, several complexes of Gd$^{3+}$, Tb$^{3+}$, and Y$^{3+}$ with N-hydroxyphthalimide with the general formula [M(NHF)$_{3}$(DMF)$_{2}$] were prepared at a 1:3 metal/ligand ratio. The Tb$^{3+}$ complex presents specific emission peaks, with the most intense peak located at 543 nm, thus being selected for incorporation in the poly(N-vinyl-pyrrolidone) matrix. The prepared complexes and composites were investigated through elemental analysis, thermal analysis, FT-IR, P-XRD, and SEM. The …

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Experimental And Computational Studies On The Absorption Properties Of Novel Formazan Derivatives, Gülşen Türkoğlu, M. Emi̇n Çinar Jan 2017

Experimental And Computational Studies On The Absorption Properties Of Novel Formazan Derivatives, Gülşen Türkoğlu, M. Emi̇n Çinar

Turkish Journal of Chemistry

Eight novel 3-(4-(benzyloxy)phenyl)-5-(4-bromophenyl)-1-(4-substituted-phenyl)formazan (4a-4h) were synthesized by coupling of substituted phenylhydrazones with diazonium salts of 4-bromoaniline. The substituted phenylhydrazones, which are intermediate products, were obtained from the condensation of substituted phenylhydrazines with 4-(benzyloxy)benzaldehyde. All target compounds were characterized by using FTIR, $^{1}$H NMR, $^{13}$C NMR, LC$-$MS spectrometry, and elemental analysis. Absorption spectra of these compounds in solvents with different polarities were investigated thoroughly. Time-dependent density functional theory (TD-DFT) studies were conducted to shed light on their electronic structures, Kohn--Sham orbitals, and electronic transitions.

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Synthesis, In Vitro Dna Interactions, Cytotoxicities, Antioxidative Activities, And Topoisomerase Inhibition Potentials Of Mn(Ii), Co(Ii), Ni(Ii), Cu(Ii), And Zn(Ii) Complexes With Azo-Oxime Ligands, Melek Çol Ayvaz, İbrahi̇m Turan, Bayram Dural, Seli̇m Demi̇r, Kaan Karaoğlu, Yüksel Ali̇yazicioğlu, Keri̇m Serbest Jan 2017

Synthesis, In Vitro Dna Interactions, Cytotoxicities, Antioxidative Activities, And Topoisomerase Inhibition Potentials Of Mn(Ii), Co(Ii), Ni(Ii), Cu(Ii), And Zn(Ii) Complexes With Azo-Oxime Ligands, Melek Çol Ayvaz, İbrahi̇m Turan, Bayram Dural, Seli̇m Demi̇r, Kaan Karaoğlu, Yüksel Ali̇yazicioğlu, Keri̇m Serbest

Turkish Journal of Chemistry

Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metal complexes of 2-hydroxy-5-[(E)-(4-phenyl) diazenyl] benzaldehyde oxime and 2-hydroxy-5-[(E)-(4-nitrophenyl) diazenyl] benzaldehyde oxime ligands were synthesized and characterized through NMR, IR, ESI mass, and UV analysis. DNA binding abilities of the complexes were revealed using a UV-Vis spectrophotometer with the absorption titration and competitive binding techniques. Hydrolytic and oxidative DNA cleavage activities under different conditions were also proved. Topoisomerase I inhibition efficiencies and in vitro free radical scavenging activities of all complexes were examined. Finally, the selective cytotoxic potentials of all complexes were evaluated in human colon cancer, normal colon, and fibroblast cell lines …

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Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo Jan 2017

Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo

Turkish Journal of Chemistry

Adsorption processes of Cd(II) and Pb(II) from aqueous solutions onto pumice stone powder (PSP) were investigated in batch mode. The influences of solution pH, contact time, adsorbent dosage, initial metal (M) concentration, and temperature on adsorption process were investigated. The kinetic and isotherm data were analysed using different model equations. The adsorption process was consistent with the Langmuir model for both metal ions with high R$^{2}$ and low $\chi^{2}$ values for both Pb(II) and Cd(II). The maximum monolayer adsorption capacities were 28.09 and 27.17 mg g$^{-1}$ for Pb(II) and for Cd(II), respectively. The pseudo-second order kinetic model explained the kinetic …

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Adsorption Of Cu(Ii) On Three Adsorbents, Fe$_{3}$O$_{4}$/Ni/Ni$_{X}$B Nanocomposite, Carob (\Textit{Ceratonia Siliqua}), And Grape Seeds: A Comparative Study, Tüli̇n Deni̇z Çi̇ftçi̇ Jan 2017

Adsorption Of Cu(Ii) On Three Adsorbents, Fe$_{3}$O$_{4}$/Ni/Ni$_{X}$B Nanocomposite, Carob (\Textit{Ceratonia Siliqua}), And Grape Seeds: A Comparative Study, Tüli̇n Deni̇z Çi̇ftçi̇

Turkish Journal of Chemistry

A novel adsorbent Fe$_{3}$O$_{4}$/Ni/Ni$_{x}$B nanocomposite was synthesized and used for the adsorption of copper. Moreover, natural adsorbents carob and grape seeds were used for this purpose. The surfaces and the elemental compositions of the adsorbents were characterized by SEM-EDX. The zero point charges of pH of Fe$_{3}$O$_{4}$/Ni/Ni$_{x}$B nanocomposite, carob, and grape seeds were found as 8.4, 6.0, and 5.6, respectively. The Langmuir, Freundlich, and Dubinin--Radushkevich isotherm models were used for the identification of the mechanism of the adsorption. The adsorptions of Cu(II) on the three adsorbents were well fitted to the Langmuir isotherm. The maximum adsorption capacities obtained from the …

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Nanocomposite Copper Metal As An Efficient Heterogeneous Catalyst In Click Synthesis Of 1,2,3-Triazoles In Aqueous Media, Vajihe Nejadshafiee, Hossein Naeimi Jan 2017

Nanocomposite Copper Metal As An Efficient Heterogeneous Catalyst In Click Synthesis Of 1,2,3-Triazoles In Aqueous Media, Vajihe Nejadshafiee, Hossein Naeimi

Turkish Journal of Chemistry

Copper/periodic mesoporous organosilica (Cu/PMO) nanocomposites provided a highly active, reusable, globular, solid-phase catalyst for click chemistry. The reaction proceeds by mixing organohalides, sodium azide, alkyne, and the catalyst in an aqueous medium to afford the desired products. The cost efficiency and recyclability of the catalyst up to six runs without appreciable loss of activity and high yields of products make this procedure greener.

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The Multiple Effects Of Organoclay And Solvent Evaporation On Hydrophobicity Of Composite Surfaces, Haci Hasan Yolcu, Ahmet Gürses, Rabah Boukherroub Jan 2017

The Multiple Effects Of Organoclay And Solvent Evaporation On Hydrophobicity Of Composite Surfaces, Haci Hasan Yolcu, Ahmet Gürses, Rabah Boukherroub

Turkish Journal of Chemistry

A superhydrophobic high-density polyethylene (HDPE)/organoclay composite material with a water-static contact angle of $\sim $162$^{\circ}$ and low hysteresis (7$^{\circ})$ was prepared by a simple solution-intercalation technique. This one-step method consists of the insertion of organoclay, produced through cation exchange with cetyltrimethylammonium bromide (CTAB), in the polymer matrix at 120 $^{\circ}$C in xylene. In this process, evaporation of the solvent and organoclay amount are key factors for the achievement of superhydrophobicity. We characterized composite material with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The characterizations showed that the organoclay provides a place for …

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Cyclic Voltammetry Behavior Of Tamoxifen In Different Electrolytes, Electrochemical Characterization, And Its Measurement By Differential Pulse Anodic Voltammetry, Zeinab Deris Falahieh, Mehdi Jalali, Mohammad Alimoradi Jan 2017

Cyclic Voltammetry Behavior Of Tamoxifen In Different Electrolytes, Electrochemical Characterization, And Its Measurement By Differential Pulse Anodic Voltammetry, Zeinab Deris Falahieh, Mehdi Jalali, Mohammad Alimoradi

Turkish Journal of Chemistry

Cyclic voltammetry (CV) was performed on tamoxifen (tam) using different electrodes and in various acidic electrolytes containing 10% v v$^{-1}$ methanol (MeOH). Tam oxidation was found to be most favorable using 0.1 mol L$^{-1}$ H$_{2}$SO$_{4}$. To investigate the mechanism, we performed chronoamperometry, CV at different scan rates, differential pulse anodic voltammetry (DPAV), and electrochemical impedance spectroscopy on tam-covered glassy carbon electrodes (GCEs). The electrode area, diffusion coefficient, and surface concentration ($\Gamma )$ of tam were calculated to be 0.062 cm$^{2}$, 3.65 $\times $ 10$^{-6}$ cm$^{2}$ s$^{-1}$, and 3.2 $\times $ 10$^{-10}$ mol cm$^{-2}$ respectively. Then the effects of different parameters …

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Methanolysis Of Jatropha Curcas Oil Using K$_{2}$Co$_{3}$/Cao As A Solid Base Catalyst, Gajanan Sahu, Sujan Saha, Sudipta Datta, Prakash Chavan, Satyanarayan Naik Jan 2017

Methanolysis Of Jatropha Curcas Oil Using K$_{2}$Co$_{3}$/Cao As A Solid Base Catalyst, Gajanan Sahu, Sujan Saha, Sudipta Datta, Prakash Chavan, Satyanarayan Naik

Turkish Journal of Chemistry

Biodiesel, fatty acid methyl ester produced by the transesterification of vegetable oil with methanol, is a promising alternative to petroleum-based diesel fuel. In the present study, the methanolysis of high free fatty acid (FFA) $Jatropha$ $curcas$ oil in a transesterification reaction using K$_{2}$CO$_{3}$/CaO solid base catalyst was studied. The various reaction parameters in the transesterification reaction were also discussed. The catalyst was characterized by means of Fourier transform infrared, X-ray diffraction, temperature programmed desorption of CO$_{2}$, scanning electron microscopy, particle size analyzer, true density, and surface area analyzer. The optimum conversion of jatropha oil was 92% when the transesterification reaction …

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Synthesis Of Novel 5-Substituted Phenyl-3-(P-Isopropylphenyl)-1-Phenylformazan And Their Biological Activities, Ayşe Şahi̇n Yağlioğlu, Hülya Şenöz Jan 2017

Synthesis Of Novel 5-Substituted Phenyl-3-(P-Isopropylphenyl)-1-Phenylformazan And Their Biological Activities, Ayşe Şahi̇n Yağlioğlu, Hülya Şenöz

Turkish Journal of Chemistry

Novel 1-substituted 3-(p-isopropylphenyl)-5-phenylformazans (3a--g) were synthesized and characterized by elemental analysis, $^{1}$H NMR, and FT-IR techniques and UV-visible spectroscopy. Antiproliferative activities of 3a--g against HeLa and C6 cells were determined using the BrdU cell proliferation ELISA assay. 5-Florouracil was used as the positive control. The effects of substituents (--H, --CH$_{3}$, and --I) and their positions ($ortho$, $meta$, and $para$) on the antiproliferative activities were evaluated. The results of the assay indicate that I substituent exhibited higher activity against the cells at the $meta$ and $para$ positions than --CH$_{3}$ and --H substituents. 3a--g exhibited both high antiproliferative activities against C6 cells …

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Separation And Recovery Of Gallium(Iii) Ions From Aqueous Phase By Liquid--Liquid Extraction Using A Novel Extractant, Cyphos Il 101, Sumitra Nayak, Niharbala Devi Jan 2017

Separation And Recovery Of Gallium(Iii) Ions From Aqueous Phase By Liquid--Liquid Extraction Using A Novel Extractant, Cyphos Il 101, Sumitra Nayak, Niharbala Devi

Turkish Journal of Chemistry

The present study describes the extraction behavior of gallium(III) using a novel ionic liquid trihexyl(tetradecyl) phosphonium chloride (Cyphos IL 101) diluted with kerosene from acidic chloride medium. The extraction of gallium was found to depend on the hydrochloric acid concentration and quantitative extraction of gallium took place at 2.0 mol/L HCl concentration. The nature of the extracted complex in the organic phase was determined using Job's method and proposed to be [R$_{3}$R$^\prime $PGaCl$_{4}$]. The loading capacity of 5.0 $\times$ 10$^{-3}$ mol/L Cyphos IL 101 was determined to be 320.0 mg/L. Two stages of stripping were required for complete removal of …

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Impurity Profiling Of Morphine By Liquid Chromatography-Heated Electrospray Ionization Mass Spectrometry (Lc-Hesi-Ms), Ana Petkovska, Jelena Acevska, Marina Chachorovska, Gjorgji Petrusevski, Gjoshe Stefkov, Rumenka Petkovska, Aneta Dimitrovska, Sonja Ugarkovic Jan 2017

Impurity Profiling Of Morphine By Liquid Chromatography-Heated Electrospray Ionization Mass Spectrometry (Lc-Hesi-Ms), Ana Petkovska, Jelena Acevska, Marina Chachorovska, Gjorgji Petrusevski, Gjoshe Stefkov, Rumenka Petkovska, Aneta Dimitrovska, Sonja Ugarkovic

Turkish Journal of Chemistry

Separation of morphine and its impurities (related substances specified in relevant European Pharmacopoeia monographs, as well as the other naturally occurring coextracted alkaloids) was obtained within a close retention window on a reverse phase HPLC column, eluted with optimized gradient, consisting of methanol and 5 mM ammonium formate, adjusted to pH 10.2. Systematic optimization of the chromatographic conditions was carried out using design of experiments. According to their mass spectra, known and specified impurities were identified and tentative structures for unknown impurities were proposed. MS analyses were performed in positive ionization mode using heated electrospray ionization. Fragmentation patterns of the …

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Investigation Of The Photophysical And Photochemical Behavior Of Substituted Zinc Phthalocyanines And Their Water-Soluble Quaternized Derivatives, Gülsev Di̇lber, Mahmut Durmuş, Hali̇t Kanteki̇n Jan 2017

Investigation Of The Photophysical And Photochemical Behavior Of Substituted Zinc Phthalocyanines And Their Water-Soluble Quaternized Derivatives, Gülsev Di̇lber, Mahmut Durmuş, Hali̇t Kanteki̇n

Turkish Journal of Chemistry

New nonperipherally and peripherally tetrasubstituted zinc(II) phthalocyanine complexes containing 1-benzylpiperidin-4-ol groups and their quaternized derivatives are reported in this work. These complexes were characterized successfully and their photophysical and photochemical properties were studied. These properties were determined in dimethylsulfoxide for all studied complexes and in water and water $+$ Triton X-100 solutions for ionic Zn(II) phthalocyanines. All studied zinc(II) phthalocyanine complexes generated high singlet oxygen, especially in dimethylsulfoxide, and these properties make them potential photosensitizers for use in the photodynamic therapy of cancer. The effects of the position and quaternization of the substituents on the photophysical and photochemical properties were …

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Naked Eye And Smartphone Applicable Detection Of Toxic Mercury Ions Using Fluorescent Carbon Nanodots, Burcu Baç, Rükan Genç Jan 2017

Naked Eye And Smartphone Applicable Detection Of Toxic Mercury Ions Using Fluorescent Carbon Nanodots, Burcu Baç, Rükan Genç

Turkish Journal of Chemistry

Chitosan passivated carbon nanodots (C-Dots$_{CHIT})$ were synthesized from expired molasses via a simple and green thermal synthesis procedure. As-synthesized C-Dots were nitrogen-doped (NC-Dots$_{CHIT})$ by posttreatment with liquid ammonia and used as nanoprobes for fluorometric detection of mercury ions (Hg(II)$_{aq.})$. Fluorescence response of NC-Dots$_{CHIT}$ in the presence of mercury was evaluated and compared with that of the polyethylene glycol passivated C-Dots$_{PEG}$. This sensing strategy using NC-Dots$_{CHIT}$ displayed a wide linear working range from 1.25 $\mu $g/mL to 43.54 $\mu $g/mL with a detection limit of 1.41 $\mu $g/mL. The fluorescence of C-Dots$_{PEG}$ did not show any significant change upon mercury addition. …

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Adaptive Fuzzy Control Of Quadrotor, Muhammad Awais Sattar Jan 2017

Adaptive Fuzzy Control Of Quadrotor, Muhammad Awais Sattar

Theses

In this thesis, intelligent controllers are designed to control attitude for quadrotor UAV (Unmanned Aerial Vehicle).Quadrotors have a variety of applications in real time e.g. surveillance, inspection, search, rescue and reducing the human force in undesirable conditions. Quadrotors are generally unstable systems; the kinematics of quadrotor resembles the kinematics of inverted pendulum. In order to avoid the possibility of any kind of damages, the mathematical model of quadrotor should be developed and after that, the different control techniques can be implemented. This thesis presents a detailed simulation model for a Quadrotor. For the control purpose, three classical and modern control …

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Multiparty Computations In Varying Contexts, Paul Laird, Sarah Jane Delany, Pierpaolo Dondio Jan 2017

Multiparty Computations In Varying Contexts, Paul Laird, Sarah Jane Delany, Pierpaolo Dondio

Conference papers

Recent developments in the automatic transformation of protocols into Secure Multiparty Computation (SMC) interactions, and the selection of appropriate schemes for their implementation have improved usabililty of SMC. Poor performance along with data leakage or errors caused by coding mistakes and complexity had hindered SMC usability. Previous practice involved integrating the SMC code into the application being designed, and this tight integration meant the code was not reusable without modification. The progress that has been made to date towards the selection of different schemes focuses solely on the two-party paradigm in a static set-up, and does not consider changing contexts. …

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Spatiotemporal Distribution Of Eutrophication In Lake Tai As Affected By Wind, Wenhui Zhang, Qiujin Xu, Xixi Wang, Xiaozhen Hu, Cheng Wang, Yan Pang, Yanbin Hu, Yang Zhao, Xiao Zhao Jan 2017

Spatiotemporal Distribution Of Eutrophication In Lake Tai As Affected By Wind, Wenhui Zhang, Qiujin Xu, Xixi Wang, Xiaozhen Hu, Cheng Wang, Yan Pang, Yanbin Hu, Yang Zhao, Xiao Zhao

Civil & Environmental Engineering Faculty Publications

One common hypothesis is that wind can affect concentrations of nutrients (i.e., nitrogen and phosphorus) and chlorophyll-a (Chl-a) in shallow lakes. However, the tests of this hypothesis have yet to be conclusive in existing literature. The objective of this study was to use long-term data to examine how wind direction and wind speed affect the spatiotemporal variations of total nitrogen (TN), total phosphorus (TP) and Chl-a in Lake Tai, a typical shallow lake located in east China. The results indicated that the concentrations of nutrients and Chl-a tended to decrease from the northwest to the southeast of Lake Tai, with …

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Water–Soil–Vegetation Dynamic Interactions In Changing Climate, Xixi Wang, Xuefeng Chu, Tingxi Liu, Xiangju Cheng, Rich Whittecar Jan 2017

Water–Soil–Vegetation Dynamic Interactions In Changing Climate, Xixi Wang, Xuefeng Chu, Tingxi Liu, Xiangju Cheng, Rich Whittecar

Civil & Environmental Engineering Faculty Publications

Previous studies of land degradation, topsoil erosion, and hydrologic alteration typically focus on these subjects individually, missing important interrelationships among these important aspects of the Earth's system. However, an understanding of water–soil–vegetation dynamic interactions is needed to develop practical and effective solutions to sustain the globe's eco-environment and grassland agriculture, which depends on grasses, legumes, and other fodder or soil-building crops. This special issue is intended to be a platform for a discussion of the relevant scientific findings based on experimental and/or modeling studies. Its 12 peer-reviewed articles present data, novel analysis/modeling approaches, and convincing results of water–soil–vegetation interactions under …

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A New Job Shop Heuristic Algorithm For Machine Scheduling Problems, Maryam Ehsaei, Duc T. Nguyen Jan 2017

A New Job Shop Heuristic Algorithm For Machine Scheduling Problems, Maryam Ehsaei, Duc T. Nguyen

Civil & Environmental Engineering Faculty Publications

The purpose of this research is to present a straightforward and relatively efficient method for solving scheduling problems. A new heuristic algorithm, with the objective of minimizing the makespan, is developed and presented in this paper for job shop scheduling problems (JSP). This method determines jobs’ orders for each machine. The assessment is based on the combination of dispatching rules e.g. the "Shortest Processing Time" of each operation, the "Earliest Due Date" of each job, the "Least Tardiness" of the operations in each sequence and the "First come First Serve" idea. Also, unlike most of the heuristic algorithms, due date …

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Heavy Metal Distribution And Groundwater Quality Assessment For A Coastal Area On A Chinese Island, Sha Lou, Shuguang Liu, Chaomeng Dai, An Tao, Bo Tan, Gangfeng Ma, Roman Sergeeyvich Chalov, Sergey Romanovich Chalov Jan 2017

Heavy Metal Distribution And Groundwater Quality Assessment For A Coastal Area On A Chinese Island, Sha Lou, Shuguang Liu, Chaomeng Dai, An Tao, Bo Tan, Gangfeng Ma, Roman Sergeeyvich Chalov, Sergey Romanovich Chalov

Civil & Environmental Engineering Faculty Publications

Chongming Island is located in the lower Yangtze Estuary in China. Due to the Leachate from a refuse landfill and the hydrodynamics of the Yangtze Estuary, the groundwater environment is particularly complicated on Chongming Island. Field observations were carried out around the landfill disposal site. The groundwater table, temperature, pH, salinity, and dissolved oxygen were measured in the field by portable equipment, and 192 water samples were collected at eight groundwater sites and one surface water site. Through laboratory analysis we found the highest measured concentration of Cr to be 54.07 μg/L, and the measured concentration of Zn was in …

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Numerical Modeling Of The Interactions Between Nonlinear Waves And Arbitrarily Flexible Vegetation, Navid Tahvildari Jan 2017

Numerical Modeling Of The Interactions Between Nonlinear Waves And Arbitrarily Flexible Vegetation, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Coastal wetlands are among the natural features with the capability to dissipate wave energy and reduce storm damage. Inadequate representation of wave and vegetation characteristics in numerical models may reduce their capability in predicting wave processes over wetlands. Previous numerical wave models have typically applied simplifications on vegetation behavior. For instance, vegetation stems were usually assumed to be rigid or semi-flexible and thus extreme stem deflections could not be captured. In this study, a time-domain nonlinear numerical model based on extended Boussinesq formulation is developed and coupled with a numerical model for vegetation blade dynamics that allows for arbitrary flexibility. …

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