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2017

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Articles 1201 - 1230 of 1499

Full-Text Articles in Chemistry

Synthesis Of Neodymium-Iron Nanoperovskite For Sensing Applications Of An Antiallergic Drug, Nada F. Atta, Mohammad H. Binsabt, Ekram H. El-Ads, Ahmed Galal Jan 2017

Synthesis Of Neodymium-Iron Nanoperovskite For Sensing Applications Of An Antiallergic Drug, Nada F. Atta, Mohammad H. Binsabt, Ekram H. El-Ads, Ahmed Galal

Turkish Journal of Chemistry

A facile route was used for the fabrication of NdFeO$_{3}$ (NF) perovskite. The orthorhombic structure of single phase nanocrystalline NdFeO$_{3}$ perovskite was confirmed by different characterization techniques: XRD, FTIR, TEM, BET, SEM, and EDAX. The nanoperovskite was successfully used as a sensor component with a carbon paste electrode (CpE) for the determination of ketotifen in pharmaceutical formulations. Ketotifen, an antiallergic drug, is utilized for the treatment of asthma attacks, rhinitis, skin allergies, and anaphylaxis. Sodium dodecyl sulfate (SDS) was employed in a surface assembly mode to improve the sensitivity of the sensor response. The proposed sensor, NdFeO$_{3}$ in situ modified …


Adsorption Isotherm Modeling Of Carbendazim And Flumetsulam Onto Homoionic-Montmorillonite Clays: Comparison Of Linear And Nonlinear Models, Yassine El Maataoui̇, Mohamadine El M'Rabet, Abdelkrim Maaroufi, Hassan Oudda, Abdelmalek Dahchour Jan 2017

Adsorption Isotherm Modeling Of Carbendazim And Flumetsulam Onto Homoionic-Montmorillonite Clays: Comparison Of Linear And Nonlinear Models, Yassine El Maataoui̇, Mohamadine El M'Rabet, Abdelkrim Maaroufi, Hassan Oudda, Abdelmalek Dahchour

Turkish Journal of Chemistry

This study deals with the adsorption of two pesticides, carbendazim and flumetsulam, from aqueous solutions onto four homoionic-montmorillonite clays (Ag$^{+}$, Zn$^{2+}$, Cu$^{2+}$, and H$^{+})$. Equilibrium adsorption isotherm data were analyzed using Freundlich, Dubinin-Radushkevich, and Temkin isotherms. Linear and nonlinear fitting methods were compared to determine the best-fitting isotherms for the experimental data. Three error analysis methods were used to evaluate the data for each method: the coefficient of determination (R$^{2})$, sum of squared errors (SSE), and chi-square test ($\chi^{2})$. Equilibrium adsorption isotherms exhibited that the carbendazim adsorption mainly involved cation exchange with homoionic-montmorillonite adsorbents. However, for flumetsulam, the main mechanisms …


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 …


Decolorization Of Reactive Orange 16 Via Ferrate(Vi) Oxidation Assisted By Sonication, Serkan Şahi̇nkaya Jan 2017

Decolorization Of Reactive Orange 16 Via Ferrate(Vi) Oxidation Assisted By Sonication, Serkan Şahi̇nkaya

Turkish Journal of Chemistry

The decolorization of azo dye C.I. reactive orange 16 (RO 16) via ferrate(VI) and sono-ferrate(VI) methods, which is the combination of the ferrate(VI) oxidation method with sonication, has been achieved in the present study. The influences of some important operating parameters, which are the initial pH, the concentration of potassium ferrate(VI) (K$_{2}$FeO$_{4})$ and the RO 16 dye, and ultrasonic density (for only the sono-ferrate(VI) method), on the color removal have been investigated. The optimum conditions have been determined as pH = 7 and [K$_{2}$FeO$_{4}$] = 50 mg L$^{-1}$ for the individual ferrate(VI) oxidation method and pH = 7 and [K$_{2}$FeO$_{4}$] …


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. …


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.


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.


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 …


A Simple And Effective Method For Determination Of The Antithyroid Drug Carbimazole Using Ruthenium Trichloride, Mukul Sharma, Afraim Koty, Abdul Jabbar Al Rajab Jan 2017

A Simple And Effective Method For Determination Of The Antithyroid Drug Carbimazole Using Ruthenium Trichloride, Mukul Sharma, Afraim Koty, Abdul Jabbar Al Rajab

Turkish Journal of Chemistry

An accurate, precise, and simple spectrophotometric method is proposed for the determination of the antithyroid drug carbimazole using ruthenium(III) chloride. This method is based on the formation at room temperature of a stable yellow-colored complex with λ$_{max}$ 370 nm. The method has a Beer's law range of 7.81 to 1.95 $\times $ 10$^{2}$ $\mu $g mL$^{-1}$, molar absorptivity coefficient $\varepsilon =$ 1.519 $\times $ 10$^{3}$ L mol$^{-1}$ cm$^{-1}$, and correlation coefficient of 0.997. The metal:ligand (M:L) ratio of the complex was confirmed by the mole ratio and Job's method of continuous variation, suggesting a 1:2 stoichiometry. The formed carbimazole:Ru(III) complex …


A Diversity-Oriented Synthesis Approach To Functionalized Azaheterocycles Using Cyclic Alpha-Halo Eneformamides, Spencer A. Langevin Jan 2017

A Diversity-Oriented Synthesis Approach To Functionalized Azaheterocycles Using Cyclic Alpha-Halo Eneformamides, Spencer A. Langevin

All Master's Theses

Functionalized piperidines, azepanes, azamacrocycles, morpholines, and thiomorpholines are common structural motifs found in a wide range of pharmaceuticals such as carmegliptine, levofloxacin, thioridazine, claviciptic acid, and azithomycin. As a result, there is a strong desire to construct highly functionalized nitrogen-bearing ring scaffolds in order to construct a wide range of drug possibilities. There are several non-modular and step-uneconomical synthetic methods used in the construction of these aforementioned motifs such as ring closing metathesis, ring expansions, and intramolecular reductive amination. In this research, we present a step-economical, cost-effective, scalable, and diversity-oriented synthesis approach to highly functionalized N-heterocycles through the intermediacy of …


Charles Holmes Herty Papers, Zach S. Henderson Library Special Collections Jan 2017

Charles Holmes Herty Papers, Zach S. Henderson Library Special Collections

Finding Aids

Collection contains notebooks, photographs, and published material concerning Charles Homes Herty's 1901 experiments that resulted in the turpentine (or Herty) cup. The experiments were partly conducted on what later became the Georgia Southern University’s Statesboro campus. Includes typescript of "Charles Holmes Herty in Statesboro," by Maxwell Taylor Courson.

Find this collection in the University Libraries' catalog.


Copper Salt-Catalyzed Formation Of A Novel Series Of Triazole-Spirodienone Conjugates With Potent Anticancer Activity., L. Gu, P. Wang, Qiu Zhong, Y. Deng, J. Xie, F. Liu, F. Xiao, Shilong Zheng, Y. Chen, Guangdi Wang, L. He Jan 2017

Copper Salt-Catalyzed Formation Of A Novel Series Of Triazole-Spirodienone Conjugates With Potent Anticancer Activity., L. Gu, P. Wang, Qiu Zhong, Y. Deng, J. Xie, F. Liu, F. Xiao, Shilong Zheng, Y. Chen, Guangdi Wang, L. He

Faculty and Staff Publications

Copper salt-catalyzed oxidative amination resulted in the formation of a novel series of triazole-spirodienone conjugates, 4-triazolyl-1-oxa-4-azaspiro[4,5]deca-6,9-dien-3,8-diones and 4-triazolyl-1-oxa-4-azaspiro[4,5]deca-6,9-dien-8-ones. A single crystal of compound 1p among them was grown and analyzed by X-ray crystallography. These compounds were evaluated for their antiproliferative activities against MDA-MB-231, HeLa, A549 and MCF-7 cell lines. Most of them showed moderate to high anticancer potency in the four cancer cell lines. The discovery of the triazole-spirodienone conjugates as cytotoxic agents against cancer cells may open up a new field in which these novel small molecules could be further explored as promising anticancer agents.


A Fast Linear Electro-Optical Effect In A Non-Chiral Bent-Core Liquid Crystal, Yuri Panarin, S.P. Sreenilayam, J.K. Vij, A. Lehmann, C. Tschierske Jan 2017

A Fast Linear Electro-Optical Effect In A Non-Chiral Bent-Core Liquid Crystal, Yuri Panarin, S.P. Sreenilayam, J.K. Vij, A. Lehmann, C. Tschierske

Articles

We report the observation of an electro-optical effect for a linear rotation of the optical axis as function of the electric field in an achiral tilted bent-core liquid crystalline compound, in which 4-cyanoresorcinol bisbenzoate core is symmetrically terminated by long linear alkyl chains (n =16) on both ends. The linear electro-optic effect observed in this material is similar to the deformed helical ferroelectric liquid crystal (DHFLC) effect reported previously in a FLC material except that dimensions of the helical pitch differ by two orders of magnitude. In the chiral systems, the helical pitch usually lies on the scale of sub-optical …


ผลของตัวเร่งปฏิกิริยาของสารประกอบเชิงซ้อนคอปเปอร์-แอมีนกับเทอเทียรีแอมีนต่อการเตรียมโฟมพอลิยูรีเทนแบบแข็ง, ชาภิชญ์ จันทรสร Jan 2017

ผลของตัวเร่งปฏิกิริยาของสารประกอบเชิงซ้อนคอปเปอร์-แอมีนกับเทอเทียรีแอมีนต่อการเตรียมโฟมพอลิยูรีเทนแบบแข็ง, ชาภิชญ์ จันทรสร

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ศึกษาเกี่ยวกับผลการเสริมกันของตัวเร่งปฏิกิริยาร่วมระหว่างสารประกอบเชิงซ้อนคอปเปอร์-แอมีนกับตัวเร่งปฏิกิริยาทางการค้าต่อการเตรียมโฟมพอลิยูรีเทนแบบแข็ง สารประกอบเชิงซ้อนคอปเปอร์-แอมีนที่สังเคราะห์ขึ้น คือ สารประกอบเชิงซ้อนคอปเปอร์-เอทิลีนไดแอมีน [Cu(OAc)2(en)2] และ สารประกอบเชิงซ้อนคอปเปอร์-ไตรเอทิลีนเตตระมีน [Cu(OAc)2(trien)] ในรูปแบบสารละลายในเอทิลีนไกลคอล ตัวเร่งปฏิกิริยาทางการค้าที่ใช้มี 3 ชนิด คือ ไดเมทิลไซโคลเฮกซิลแอมีน (DMCHA) และไตรเอทิลีนไดแอมีน (TEDA) ซึ่งเป็นตัวเร่งปฏิกิริยาประเภทเทอเทียรีแอมีน และโพแทสเซียมออกโทเอต (KOct) พิสูจน์เอกลักษณ์ของสารประกอบเชิงซ้อนคอปเปอร์-แอมีนโดยใช้เทคนิคยูวี-วิสิเบิลสเปกโทรสโกปี และเอฟทีไออาร์สเปกโทรสโกปี ศึกษาการเตรียมโฟมพอลิยูรีเทนแบบแข็งด้วยระบบตัวเร่งปฏิกิริยาร่วม 6 ระบบ คือ Cu(OAc)2(en)2 : DMCHA, Cu(OAc)2(trien) : DMCHA, Cu(OAc)2(en)2 : TEDA, Cu(OAc)2(trien) : TEDA, Cu(OAc)2(en)2 : KOct และ Cu(OAc)2(trien) : KOct โดยศึกษาเวลาที่ใช้ในการเกิดปฏิกิริยา คือ เวลาเกิดครีม, เวลาเกิดเจล, เวลาที่โฟมไม่เกาะติดกับผิววัสดุ และเวลาที่โฟมหยุดฟู พิสูจน์เอกลักษณ์โฟมที่ได้ด้วยเอทีอาร์-เอฟทีไออาร์สเปกโทรสโกปี จากผลการทดลองพบว่าตัวเร่งปฏิกิริยาร่วม Cu(OAc)2(en)2 : DMCHA และ Cu(OAc)2(trien) : DMCHA สามารถเร่งปฏิกิริยาได้เร็วกว่าการใช้ตัวเร่งปฏิกิริยาชนิดเดียว คือ Cu(OAc)2(en)2 หรือ Cu(OAc)2(trien) หรือ DMCHA โดยดูได้จากเวลาที่โฟมไม่เกาะติดกับผิววัสดุมีค่าลดลง โฟมพอลิยูรีเทนแบบแข็งที่เตรียมได้จาก Cu(OAc)2(en)2 : DMCHA และ Cu(OAc)2(trien) : DMCHA มีสมบัติเชิงกายภาพและสมบัติเชิงกลที่ดีเทียบเท่ากับโฟมที่เตรียมจาก DMCHA


Spectroscopic Analysis Of The Traditional Cyanotype Process And Its Impact On Art, Jacob Applegarth Jan 2017

Spectroscopic Analysis Of The Traditional Cyanotype Process And Its Impact On Art, Jacob Applegarth

Undergraduate Honors Thesis Collection

Reflectance spectroscopy was used to study the cyanotype printing process. Originally this process was used to make photocopies of building designs, but today it is used for art. The cyanotype process is a photo catalyzed oxidation-reduction reaction. This study altered the concentrations and reagents involved in the printing process, and it included the use of ammonium ferricyanide and ammonium iron(III) oxalate along with the traditional potassium ferricyanide and ammonium iron(III) citrate. The impact of these changes on the rate of formation of Prussian blue was observed and quantified. Rate laws and general trends were determined for the reagents involved. Qualitative …


In Situ Ph Determination Based On The Nmr Analysis Of ¹H-Nmr Signal Intensities And ¹⁹F-Nmr Chemical Shifts, Ming Huang Jan 2017

In Situ Ph Determination Based On The Nmr Analysis Of ¹H-Nmr Signal Intensities And ¹⁹F-Nmr Chemical Shifts, Ming Huang

Masters Theses

"The pH of an NMR sample can be measured directly by NMR experiments of signal intensities, chemical shifts, or relaxation time constants that depend on the pH. The 1H NMR peak intensities of the pH indicator phenolphthalein change as it changes from the OH-depleted form to the OH-rich form in the range of pH = 11.1 to 12.7. Because this range is rather small, another NMR technique was utilized based on 19F chemical shifts. The shift of F- in an aqueous solution of NaF changes in the alkaline range between pH = 11.0 and 14.0 and even …


Sonochemical Degradation Of Basic Red 29 In Aqueous Media, Zineb Boutamine, Slimane Merouani, Oualid Hamdaoui Jan 2017

Sonochemical Degradation Of Basic Red 29 In Aqueous Media, Zineb Boutamine, Slimane Merouani, Oualid Hamdaoui

Turkish Journal of Chemistry

In this work, the degradation of Basic Red 29 (BR29), an azo dye, was investigated using a high-frequency ultrasonic reactor (300 kHz). The influence of several parameters such as initial substrate concentration (5--200 mg L$^{-1})$, pH (3-10.1), ultrasonic power (20-80 W), and nature of the dissolved gas (Ar, air, and N$_{2})$ on the degradation of BR29 was assessed. Additionally, the impact of natural matrices (seawater and natural and river waters) on the degradation rate of BR29 was clarified. Degradation experiments with radical scavengers, tert-butyl alcohol and glucose, showed that BR29 degraded mainly through HO$^{\bullet }$ radical attack at the gas/liquid …


Synthesis, Characterization, And Antimicrobial Activities Of Novel Monosaccharide-Containing Schiff Base Ligands, Fatma Telli̇, Stephen Thomas Astley, Azi̇ze Yeşi̇m Salman Jan 2017

Synthesis, Characterization, And Antimicrobial Activities Of Novel Monosaccharide-Containing Schiff Base Ligands, Fatma Telli̇, Stephen Thomas Astley, Azi̇ze Yeşi̇m Salman

Turkish Journal of Chemistry

Four new chiral Schiff base ligands (3a-4a, 3b-4b) have been prepared using aminoisopropylidene derivatives of glucose and aminochloralose derivatives of mannose. The synthesized compounds 1 and 2 were characterized by nuclear magnetic resonance ($^{1}$H and $^{13}$C NMR), Fourier transform infrared spectroscopy (FTIR), UV/visible spectroscopy, and elemental analysis. A total of eight Schiff base compounds (3a-6a, 3b-6b) were tested for antimicrobial activity against Escherichia coli ATCC 12228, Staphylococcus aureus ATCC 6538, Klebsiella pneumoniae CCM 2318, Pseudomonas aeruginosa ATCC 27853, Salmonella typhimurium CCM 5445, Enterococcus faecalis ATCC 29212, Bacillus subtilis ATCC 6633, and Candida albicans ATCC 10239 and exhibited a range of …


Synthesis Of Na-, Fe-, And Co-Promoted Tio$_{2}$/Multiwalled Carbon Nanotube Composites And Their Use As A Photocatalyst, Alp Yürüm, Gürkan Karakaş Jan 2017

Synthesis Of Na-, Fe-, And Co-Promoted Tio$_{2}$/Multiwalled Carbon Nanotube Composites And Their Use As A Photocatalyst, Alp Yürüm, Gürkan Karakaş

Turkish Journal of Chemistry

The use of multiwalled carbon nanotubes (CNTs) in sol-gel synthesized titanium dioxide (TiO$_{2})$ photocatalysts as templates was systematically studied. CNTs have high oxidative thermal stability and the controlled removal of CNTs can be achieved at lower temperatures under air flow by the use of Na, Fe, and Co as a catalyst. These catalysts helped to reduce the oxidation temperature of CNTs; thus anatase phase was achieved without significant sintering. The use of a promoter, heat treatment, and various heat treatment atmospheres was effective in specific surface area, crystallinity, and photocatalytic activity against methylene blue (MB) degradation. While the specific surface …


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 …


Catalytic Application Of 1,3,5-Triazine-Pentaethylenehexamine Polymer-Supported Palladium Nanoparticles In The Convenient Reduction Of Nitroarenes With Sodium Borohydride Or Hydrazine, Hayri̇ye Genç, Mustafa Zengi̇n, Mustafa Küçüki̇slamoğlu, Mustafa İmamoğlu, Hüseyi̇n Özkan Toplan, Mustafa Arslan Jan 2017

Catalytic Application Of 1,3,5-Triazine-Pentaethylenehexamine Polymer-Supported Palladium Nanoparticles In The Convenient Reduction Of Nitroarenes With Sodium Borohydride Or Hydrazine, Hayri̇ye Genç, Mustafa Zengi̇n, Mustafa Küçüki̇slamoğlu, Mustafa İmamoğlu, Hüseyi̇n Özkan Toplan, Mustafa Arslan

Turkish Journal of Chemistry

The catalytic activity of 1,3,5-triazine-pentaethylenehexamine (TAPEHA) polymer-supported Pd nanoparticles was investigated in the reduction of nitro arenes to the corresponding amines by NaBH$_{4}$ or N$_{2}$H$_{4}$.H$_{2}$O. Optimized reaction conditions for both systems were successfully tested on 20 nitroarenes with different characteristics. Considerably high yields (80%-98% in NaBH$_{4}$ and 85%-98% in N$_{2}$H$_{4})$ were obtained in a short time and at ambient temperature. In addition to these methods being selective against other reducible functionalities such as -CN, -Br, -Cl, and -I, the catalyst can be recovered easily and reused more than ten times.


Synthesis Of Pds/Zns--Cds-Type Photocatalysts Using Zns As Sulphide Source, Radu Banica, Petrica Linul, Cristina Mosoarca Jan 2017

Synthesis Of Pds/Zns--Cds-Type Photocatalysts Using Zns As Sulphide Source, Radu Banica, Petrica Linul, Cristina Mosoarca

Turkish Journal of Chemistry

In this work, a new method for the growth of large CdS crystals into PdS/ZnS--CdS-type photocatalysts is presented. In order to accomplish this, in the first stage zinc sulphide was synthesised and hydrothermally crystallised. In the second stage, after PdS decoration, the recrystallised zinc sulphide was utilised as sulphur source for the synthesis of PdS/ZnS--CdS-type photocatalysts. The photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. In the third stage magnetic polymer supports were manufactured and loaded with photocatalyst. Finally photocatalysis experiments under blue light illumination were conducted for the hydrogen evolution …


Influence Of Magnetic Nanoparticles And Magnetic Stress On An Ionic Liquid Electrospray Source, Kurt Joseph Terhune Jan 2017

Influence Of Magnetic Nanoparticles And Magnetic Stress On An Ionic Liquid Electrospray Source, Kurt Joseph Terhune

Dissertations, Master's Theses and Master's Reports

Two electrospray sources were developed to operate on an ionic liquid ferrofluid; one source was a pressure‑fed capillary electrospray source and the other was a novel electrospray source which used a magnetically‑induced instability to produce a peak from which an electric field could extract electrospray. Multiple characteristics of electrospray operation were examined for both sources using faraday plates/cups, a quartz crystal microbalance, a retarding potential analyzer, and a time-of-flight mass spectrometer. The ILFF electrosprays for a capillary source were shown to operate in a mixed ion/droplet regime. The mass flow of the electrospray beam was primarily transported by larger particles …


Metallosalen-Based Polymers For Reduction Of Carbon Dioxide, Cherawat Kaewyai Jan 2017

Metallosalen-Based Polymers For Reduction Of Carbon Dioxide, Cherawat Kaewyai

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this research, a series of novel asymmetric copper- and nickel-salens bearing thiophene-based substituents were successfully synthesized and characterized by nuclear magnetic resonance spectroscopy and mass spectrometry. Homogeneous electrocatalytic activities of these monomers toward reduction of CO2 were investigated using cyclic voltammetry technique. Electrochemical studies showed these salen monomers are able to serve as catalysts in the electrochemical reduction of CO2 due to the significantly increase of the current observed under CO2-saturated condition, compared with those found under the N2-saturated one. Results also revealed that insertion of the carbon-carbon triple-bond between the thiophene-based substituents and the salen core led to …


ไฮโดรจิเนชันของคาร์บอนไดออกไซด์เป็นโอเลฟินส์บนตัวเร่งปฏิกิริยาเหล็กและโคบอลต์บนคาร์บอน, เจนจิรา รัตถิวัลย์ Jan 2017

ไฮโดรจิเนชันของคาร์บอนไดออกไซด์เป็นโอเลฟินส์บนตัวเร่งปฏิกิริยาเหล็กและโคบอลต์บนคาร์บอน, เจนจิรา รัตถิวัลย์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อเตรียมคาร์บอนทรงกลมในการนำมาใช้เป็นตัวรองรับสำหรับการเตรียมตัวเร่งปฏิกิริยาและศึกษากระบวนการไฮโดรจิเนชันของคาร์บอนไดออกไซด์เป็นโอเลฟินส์บนตัวเร่งปฏิกิริยาเหล็กและโคบอลต์บนคาร์บอนทรงกลมที่เตรียมได้ โดยสามารถเตรียมคาร์บอนทรงกลมจากไซโลสด้วยวิธีไฮโดรเทอร์มอลคาร์บอไนเซชัน โดยตัวเร่งปฏิกิริยาโคบอลต์ที่เตรียมจากตัวรองรับคาร์บอนทรงกลม (10%Co/CS-IMP) มีประสิทธิภาพที่ดีกว่าเมื่อเทียบกับตัวเร่งปฏิกิริยาโคบอลต์ที่เตรียมจากตัวรองรับเส้นใยซิลิกาและซิลิกา (10%Co/SF-IMP, 10%Co/SiO2-IMP) จากนั้นทำการศึกษาเปรียบเทียบระหว่างใช้ตัวเร่งปฏิกิริยาโลหะเดี่ยว (10%Co/CS-IMP) และตัวเร่งปฏิกิริยาโลหะคู่ที่มีตัวส่งเสริม (10%(Co-Fe)/K/CS-IMP) พบว่า ตัวส่งเสริมโพแทสเซียมช่วยทำให้ปฏิกิริยาเกิดสารไฮโดรคาร์บอนโอเลฟินส์ ทำการเปรียบเทียบการเตรียมตัวเร่งปฏิกิริยาด้วยวิธีเคลือบฝัง (Impregnation, IMP) และวิธีไฮโดรเทอร์มอลคาร์บอไนเซชัน (Hydrothermal carbonization, HC) พบว่าวิธีเคลือบฝังให้ตัวเร่งปฏิกิริยาที่มีประสิทธิภาพในการเร่งปฏิกิริยาไฮโดรจิเนชันของคาร์บอนไดออกไซด์ และจากการศึกษาสภาวะที่เหมาะสมในการทำปฏิกิริยาไฮโดรจิเนชันของคาร์บอนไดออกไซด์ พบว่า ที่ความดันที่ 25 บาร์, อุณหภูมิที่ใช้ทำปฏิกิริยา เท่ากับ 300 องศาเซลเซียส, ค่าอัตราส่วนของน้ำหนักตัวเร่งปฏิกิริยาต่ออัตราเร็วของสารป้อน (W/F) เท่ากับ 10 กรัม(ตัวเร่งปฏิกิริยา)·ชั่วโมง/โมล โดยใช้ตัวเร่งปฏิกิริยา 15%(Co-Fe)/K/CS-IMP ให้ประสิทธิภาพที่ดีที่สุดในการเร่งปฏิกิริยาไฮโดรจิเนชันของคาร์บอนไดออกไซด์ โดยให้ค่าร้อยละการเปลี่ยนของคาร์บอนไดออกไซด์ที่สูงที่สุด เท่ากับ ร้อยละ 59.98 มีค่าร้อยละการเลือกเกิดและร้อยละผลผลิตของสารไฮโดรคาร์บอนโอเลฟินส์ เท่ากับ ร้อยละ 11.17 และ 6.50 ตามลำดับ และทำการศึกษาคุณลักษณะของตัวเร่งปฏิกิริยาด้วยเทคนิคการวิเคราะห์อุณหภูมิของการรีดิวซ์ตัวเร่งปฏิกิริยา, เทคนิคการดูดซับทางกายภาพด้วยแก๊สไนโตรเจน, เทคนิคการเลี้ยวเบนของรังสีเอกซ์ และการศึกษาลักษณะทางสัณฐานวิทยาของด้วยกล้องจุลทรรศน์อิเล็กตรอนแบบส่องกราด


Characterization Of Non-Volatile Chemical Constituents In Thai Wineusing Liquid Chromatography-Tandem Mass Spectrometry, Premkamol Karapakdee Jan 2017

Characterization Of Non-Volatile Chemical Constituents In Thai Wineusing Liquid Chromatography-Tandem Mass Spectrometry, Premkamol Karapakdee

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed and validated for simultaneous determination of targeted non-volatile compounds, such as five organic acids and twenty phenolic compounds, in 19 wine samples including 2 imported red wines, 15 Thai red wines and 2 fruit wines, using the following HPLC-MS/MS conditions: a C18 analytical column and gradient elution of A: B mobile phase at flow rate 0.4 mL/min, where A and B are 0.1% v/v formic acid in water and 0.1% v/v formic acid in methanol. The limit of detection (LOD) and the limit of quantitation (LOQ) for these …


Anti-Angiogenic And Cytotoxic Activities Of Rotenoids From Derris Trifoliata Lour., Yanisa Mittraphab Jan 2017

Anti-Angiogenic And Cytotoxic Activities Of Rotenoids From Derris Trifoliata Lour., Yanisa Mittraphab

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to isolate metabolites of D. trifoliata stem and to evaluate their cytotoxic and anti-angiogenic activities. Chromatographic fractionation of the EtOAc led to the isolation of eight known rotenoids (1-2, 4-6, 11-12 and 15). All compounds were first evaluated for their cytotoxicity against three cancer cell lines; human cervical carcinoma (CaSki), colon cancer (HCT-116), hepato carcinoma (Hep-G2) and normal human colon epithelial (CCD841) cells. All Compounds showed cytotoxicity against HCT-116 with IC50 ranging 0.12-11.21 µM, while they were weak or no activity against Hep-G2 and CaSKi cells. Moreover, it was found that 12a-hydroxyrotenone (11) potently inhibited migration of …


Modification Of Panobinostat To Increase Its Therapeutic Potential To Cure Multiple Myeloma, Sweta Adhikari Jan 2017

Modification Of Panobinostat To Increase Its Therapeutic Potential To Cure Multiple Myeloma, Sweta Adhikari

Honors Theses

Panobinostat is a potent histone deacetylase inhibitor that can impede function of a wide range of zinc-dependent histone deacetylases. Panobinostat is the first approved histone deacetylase inhibitor for the treatment of multiple myeloma, along with other drugs such as Velcade and Dexamethasone. Simplistically, it helps to shrink or eradicate tumor growth in multiple myeloma patients. However, the treatment has severe adverse effects due to its lack of selectivity. In collaboration with Dr. Shana Stoddard (Rhodes College, Memphis TN) and Fatima Rivas (St. Jude's Research Hospital, Memphis TN), our research aims to design a more selective model of panobinostat that binds …


Quercitrin And Afzelin Isolation: Chemical Synthesis Of A Novel Methicillin-Resistant Staphylococcus Aureus (Mrsa) Antibiotic Analogue, Taylor Ramsaroop Jan 2017

Quercitrin And Afzelin Isolation: Chemical Synthesis Of A Novel Methicillin-Resistant Staphylococcus Aureus (Mrsa) Antibiotic Analogue, Taylor Ramsaroop

Honors Theses

The increasing prevalence of bacterial resistance to antibiotics is an epidemic where once easily treated infectious illnesses are becoming more difficult to treat, leading to prolonged suffering, exacerbated medical costs, and sometimes death. Methicillin-Resistant S. aureus (MRSA) is a strain of the Staph Infection causing bacteria that is resistant to penicillin-like beta lactam antibiotics and occurs at a high incidence in several countries in Europe, the Americas, and the Asia-Pacific region. In a routine screening of plant extracts, an extract of American Sycamore leaves (Plantus occidentalis) was noted to show promising activity against the experimental MRSA strain included in the …


An Analysis Of Stimuli Responsive Biomaterials Using Raman Spectroscopy And Computational Studies, Gretchen Harknett Jan 2017

An Analysis Of Stimuli Responsive Biomaterials Using Raman Spectroscopy And Computational Studies, Gretchen Harknett

Honors Theses

This thesis involves the computational and spectroscopic exploration of the linear dendritic block copolymer, poly(L-lactide)-poly(amido-amine), (PLA-PAMAM), under different environmental conditions using Raman spectroscopy, in hopes to utilize it in future effective and cost-efficient drug delivery systems. Janus dendrimers, a material made up of two different dendrimer portions, are currently being studied in great detail, as they possess many attractive features for materials scientists looking to develop ways for drugs to be delivered in more efficient manners than currently available to physicians. The instrumentation used to conduct this thesis is a high resolution Raman spectrometer. Computationally, Gaussian 09 was employed to …