Browsing by Publisher "Taylor and Francis Inc."

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    A comparison of inverted spinal traction and conventional traction in the treatment of lumbar disc herniations
    (Taylor and Francis Inc., 2000) Güevenol K.; Tüzün Ç.; Peker Ö.; Göktay Y.
    The purpose of this investigation of lumbar disc herniation patients was to compare the efficacy of the inversion spinal traction and the conventional mechanical spinal traction on several clinical parameters and computed tomography. This investigation consisted of 29 patients with low back pain and sciatica due to lumbar disc herniation. Patients were randomly assigned into two groups: an inversion spinal traction that was applied to 15 patients, and a conventional traction that was applied to 14 patients for ten sessions. The efficacy of the treatments was evaluated based upon clinical parameters before, immediately after, and three months after the treatment. Computed tomographic (CT) investigation was done before and immediately after the treatment. Both methods of traction were found to be clinically effective. Although there was no statistically significant difference between the two groups based upon the clinical parameters, CT findings of the conventional traction group tended to show more improved parameters than the inverted spinal traction group. Reasons for better results of the conventional traction are discussed and the necessity for further investigations on this topic is emphasized.
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    Removal of lead (II) ions from aqueous solution by using crosslinked chitosan-clay beads
    (Taylor and Francis Inc., 2012) Tirtom V.N.; Dinçer A.; Becerik S.; Aydemir T.; Çelik A.
    A simple and effective biodegradable material known as chitosan-clay composite beads were prepared to remove Pb(II) ions from aqueous solution. For this purpose, various important parameters such as contact time, pH and temperature were examined on the adsorption of Pb(II) ions onto crosslinked chitosan-clay composite beads. Maximum adsorption capacity of Pb(II) was observed at pH 4.5 and 25°C and calculated as 7.93 mg/g according to Langmuir isotherm model. Thermodynamic parameters namely ΔG°, ΔH° and ΔS° of the Pb(II) adsorption process have been calculated as 7.889 kJ/mol, -15.131 kJ/mol and -0.0785 kJ/molK respectively. EDTA was the best eluent for the desorption of Pb(II) ions from the crosslinked chitosan-clay beads. Scanning electron microscope (SEM) was used to characterize the surface morphology of the crosslinked chitosan-clay beads. © 2012 Desalination Publications.
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    Synthesis and luminescence properties of trivalent rare-earth element-doped calcium stannate phosphors
    (Taylor and Francis Inc., 2014) Karabulut Y.; Ayvacikli M.; Canimoglu A.; Guinea J.G.; Kotan Z.; Ekdal E.; Akyuz O.; Can N.
    The phosphors of calcium stannate activated with individual trivalent rare-earth element (REE) ions (Neodymium III, Europium III, Terbium III, Dysprosium III, and Samarium III) were synthesized by high-temperature solid-state reaction (SSR), and their characterization and luminescent properties were investigated. The crystal structures and morphologies of the resultant materials were well characterized by experimental techniques such as X-ray powder diffraction (XRD) and environmental scanning electron microscopy (ESEM). The XRD results display that the rare-earths substitution of Calcium II does not change the structure of calcium stannate host. Obviously, the ESEM image exhibits that phosphors aggregate and their particles with irregular shape exist. The calcined powders of the Europium III, Neodymium III, Samarium III, Dysprosium III, and Terbium III ions doped in calcium stannate exhibits bright red, reddish orange, yellowish, orange white, and green light, respectively. Although there is some intrinsic emission ranging from UV to near-infrared (NIR) due to the host lattice, the dominant signals are from the rare-earth sites, with signals characteristic of the trivalent rare-earth states. The emission spectrum from undoped-calcium stannate phosphor is characterized by two broad bands centered at ∼800 and ∼950 nm. The shapes of the emission bands are different for each dopant. The sharp emission properties show that the calcium stannate is a suitable host for rare-earth ion-doped phosphor material. Furthermore the influence of different rare-earth dopants, that is, Europium III, Neodymium III, Samarium III, Dysprosium III, and Terbium III, on thermally stimulated luminescence (TSL) of calcium stannate phosphor under the beta irradiation was discussed. Among these trivalent rare-earth-doped phosphors samarium-doped material showed maximum TSL sensitivity with favorable glow curve shape. © 2014 Copyright Taylor & Francis Group, LLC.
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    Strong visible and near-infrared cathodoluminescence in alkali feldspar
    (Taylor and Francis Inc., 2014) Karabulut Y.; Canimoglu A.
    In this study, cathodoluminescence (CL) spectroscopy at direct current and alternating current under the sample temperature condition of 40-293 K using different modulation frequencies is presented for alkali feldspar from the Dartmoor granite (UK). These feldspars contain strain-controlled lamellar crypto-and microperthites that are cross-cut by strain-free deuteric microperthites. The CL spectra of the alkali feldspar at room and low temperature confirm that the observed emission peaked at ∼460 nm could be associated with Al-O--Al or Ti impurity centers, yellow emission ∼560 nm could be associated with the presence of the centers such as radiation-induced defect centers, and ∼756 nm emission could be associated with the Fe3+ impurity center on T1 and T2 sites. The consequence of their association is to produce different luminescence properties such as intensity, peak wavelength, and band shape. © 2014 Copyright Taylor & Francis Group, LLC.
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    Fluorescence, thermal, electrochemical, and morphological properties of new poly(Urethane-İmide)s: Synthesis and characterization
    (Taylor and Francis Inc., 2014) Avci A.; Şirin K.
    New thermally stable poly(urethane-imide)s (PUIs) were synthesized to investigate aliphatic and aromatic group effects on various properties such as thermal stability and electrochemical properties. Thermal characterizations were carried out by TG-DTA and DSC techniques. TGA results showed that the PUIs derived from aromatic diisocyanates had relatively higher thermal stabilities as compared to the aliphatic diisocyanate. They have between 223-245°C onset temperature and above 37% char at 1000°C. Also, thermal degradation values show that PUIs have higher stability than conventional PU. DSC results showed that the new PUIs have Tg values between 134 and 138°C. Fluorescence measurements were performed using dimethyl sulfoxide solutions and also, the optimization of the concentrations maximal emission intensity was investigated in dimethyl sulfoxide. As a result, the remarkable properties related to the fluorescence and thermal measurements of the polymers were obtained. Therefore, these polymers could be used in various application fields because of the fluorescent and thermal properties. © Taylor & Francis Group, LLC.
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    Soft computing methods for thermo-acoustic simulation
    (Taylor and Francis Inc., 2014) Selimefendigil F.; Öztop H.F.
    In the present study, soft computing methods are employed for thermoacoustic simulation. A ducted Burke-Schumann diffusion flame is used as the heat source for a horizontal duct. First, a dynamic model is constructed from the input-output data sets (velocity forcing - heat release) generated from the Burke-Schumann flame using Comsol. An efficient and cheap model of heat source is obtained using dynamic fuzzy identification. The full thermoacoustic system is simulated in a time domain with the Galerkin method using the identified heat source model. Finally, dynamic neural networks are utilized for obtaining a dynamic fit for a set of operating conditions for the acoustic velocity at the heater location. The overall agreement between the outputs of the soft computing tools (fuzzy and neural network tools) with the Comsol and Galerkin solver is found to be satisfactory. © 2014 Taylor & Francis Group, LLC.
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    Characterization of a green-emitting copper-doped barium aluminate phosphor
    (Taylor and Francis Inc., 2014) Ayvacikli M.
    A novel green-emitting phosphor copper-doped barium aluminate was synthesized by the conventional ceramic method. The crystallographic phase and microstructure identification were performed by powder X-ray diffraction and scanning electron microscopy. The X-ray diffraction pattern of the sample confirms the formation of the phosphor, and the scanning electron microscope image was recorded to observe the surface morphology. Differential thermal analysis results show that the initiatory decomposition temperature of barium carbonate starts at about 728°C. Cathodoluminescence studies have been undertaken to ensure the successful incorporation of copper ions in the barium aluminate host lattice. Under the excitation of the electron beam, the phosphor can efficiently display a broad green emission centered at 490 nm, corresponding to the transition from the conduction band edge to the excited state of copper in the barium aluminate host. However, there are no data available on copper luminescence in barium aluminate. New results on 3d activators of copper emission in the barium aluminate host are reported in this article, thus extending the list of copper-activated phosphors. These results strongly indicate that the copper-activated barium aluminate is a potential material used as a new high-brightness green phosphor for ultraviolet light-emitting diode and display devices. © 2014 Copyright Taylor & Francis Group, LLC.
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    Synthesis and characterization of chloralose-derived thiosemicarbazones and semicarbazones and investigation of their antimicrobial properties
    (Taylor and Francis Inc., 2014) Yetgin C.E.; Oskay M.; Ay K.
    Thiosemicarbazones(7-10)/semicarbazones(11-14) were synthesized in good yields via the condensation of α-gluco-, β-gluco-, galacto-, manno- chloralose derived 1,4-furanodialdoses (1-4) with thiosemicarbazide(5)/ semicarbazide(6). The structures of all products were characterized by FTIR, NMR spectroscopic methods and elemental analysis. The compounds have been found to display moderate antimicrobial activity against Gram-positive, Gram-negative bacteria and antifungal activity against a Candida albicans. MIC values of the compounds range from 260 to 1510 g/mL. © 2014 Taylor & Francis Group, LLC.
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    Immobilization of amyloglucosidase onto macroporous cryogels for continuous glucose production from starch
    (Taylor and Francis Inc., 2015) Uygun M.; Akduman B.; Ergönül B.; Aktaş Uygun D.; Akgöl S.; Denizli A.
    Poly(methyl methacrylate-glycidyl methacrylate) [Poly(MMA-GMA)] cryogels were synthesized using monomers of methylmethacrylic acid and epoxy group bearing GMA via radical cryopolymerization technique. Synthesized cryogels were used for the immobilization of amyloglucosidase to the cryogel surface using epoxy chemistry. Characterizations of the free and immobilized amyloglucosidase were carried out by comparing the optimum and kinetic parameters of enzymes. For this, pH and temperature profiles of free and immobilized preparation were studied and, it was found that, optimum pH of enzyme was not change upon immobilization (pH 5.0), while optimum temperature of the enzyme shifted 10 °C to warmer region after immobilization (optimum temperatures for free and immobilized enzyme were 55 and 65 °C, respectively). Kinetic parameters of free and immobilized enzyme were also investigated and Km values of free and immobilized amyloglucosidase were found to be 2.743 and 0.865 mg/mL, respectively. Vmax of immobilized amyloglucosidase was found to be (0.496 mol/min) about four times less than that of free enzyme (2.020 mol/min). Storage and operational stabilities of immobilized amyloglucosidase were also studied and it was showed that immobilized preparation had much more stability than free preparation. In the present work, amyloglucosidase immobilized poly(MMA-GMA) cryogels were used for continuous glucose syrup production from starch for the first time. Efficiency of immobilized enzyme was investigated and released amount of glucose was found to be 2.54 mg/mL at the end of the 5 min of hydrolysis. The results indicate that the epoxy functionalized cryogels offer a good alternative for amyloglucosidase immobilization applications with increased operational and thermal stability, and reusability. Also, these cryogels can be used for immobilization of other industrially valuable enzymes beyond amyloglucosidase. © 2015 Taylor & Francis.
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    Effects of shear stresses and rotary inertia on the stability and vibration of sandwich cylindrical shells with FGM core surrounded by elastic medium
    (Taylor and Francis Inc., 2016) Sofiyev A.H.; Hui D.; Valiyev A.A.; Kadioglu F.; Turkaslan S.; Yuan G.Q.; Kalpakci V.; Özdemir A.
    The vibration and stability of axially loaded sandwich cylindrical shells with the functionally graded (FG) core with and without shear stresses and rotary inertia resting Pasternak foundation are investigated. The dynamic stability is derived based on the first order shear deformation theory (FSDT) including shear stresses. The axial load and dimensionless fundamental frequency for FG sandwich shell with shear stresses and rotary inertia and resting on the Pasternak foundation. Finally, the influences of variations of FG core, elastic foundations, shear stresses and rotary inertia on the fundamental frequencies and critical axial loads are investigated. © 2016, Copyright © Taylor & Francis Group, LLC.
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    Removal of erythrosine dye from aqueous solutions using magnetic chitosan with erythrosine as imprinted molecules
    (Taylor and Francis Inc., 2016) Eser A.; Aydemir T.; Becerik S.; Dinçer A.
    A novel, chitosan coating on the surface of magnetite (Fe3O4) (erythrosine-imprinted magnetic chitosan (EIMC)) was successfully synthesized using erythrosine (ER) as a template for adsorption and the removal of ER from aqueous solutions. Characterization of the obtained EIMC was achieved by FTIR spectra, SEM micrographs, and TGA analysis. Batch adsorption experiments of EIMC and non-imprinted magnetic chitosan (NIMC) were performed to investigate the adsorption conditions. The results showed that the maximum adsorption capacity for EIMC and NIMC was observed at pH 6 and temperature 40°C. Equilibrium adsorption was achieved within 3 h. Adsorption process could be well described by Freundlich adsorption isotherms. Thermodynamic parameters namely ΔG°, ΔH°, and ΔS° of the ER adsorption process were calculated. The negative values of Gibbs free energy of adsorption (ΔG°) indicated the spontaneity of the adsorption of ER dye on the EIMC and NIMC. Desorption of ER from EIMC and NIMC could be done rapidly using 0.1 M NaOH solution and the beads could be used again to remove ER. Results show that imprinting technique increases the removal amount of ER dye from aqueous solutions. © 2015 Balaban Desalination Publications. All rights reserved.
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    Application of Exogenous Sodium Nitroprussid Alleviates Boron Toxicity in Wheat Seedlings: Investigation of Thiol Compounds, Macro/Micronutrient, and Polyamine Contents
    (Taylor and Francis Inc., 2016) Dilek Tepe H.; Aydemir T.
    High boron (B) levels in the soil reduce plant growth and yield production in crop plants. Nitric oxide (NO) is a highly reactive signaling molecule involved in stress response in plants. The aim of the study was to investigate the role of sodium nitroprussid (SNP), a NO donor, in alleviating the B-induced toxicity in two wheat cultivars. Both cultivars were treated with 10 mM B, 10 mM B + 0.1 mM SNP, 10 mM B + 0.2 mM SNP, and 10 mM B + 0.5 mM SNP. The nutrient contents were investigated via inductively coupled plasma mass-spectrometry. Contents of polyamines and thiol compounds were analyzed by high-performance liquid chromatography. The B toxicity caused a significant decrease in nutrient contents and thiol compounds, but increased polyamine contents. However, exogenous application of 0.2 mM SNP increased nutrient contents and thiol compounds, but lowered polyamine contents. The study clearly revealed that exogenous SNP can overcome the toxic effects of B on wheat seedlings. © 2016 Taylor & Francis.
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    A novel Turkish natural zeolite (clinoptilolite) treated with hydrogen peroxide for Ni2+ ions removal from aqueous solutions
    (Taylor and Francis Inc., 2016) Çanli M.; Abali Y.
    The removal of Ni(II) from aqueous solution by batch adsorption technique using a novel Turkish zeolite from Akdere region was investigated. Activation of the zeolite was achieved with hydrogen peroxide. After elementary characterization of the adsorbent, the influence of contact time, pH, adsorbent amount, initial Ni(II) concentration, and temperature on the selectivity of the removal process was investigated. Results showed that increase in adsorbent dosage led to increase in Ni(II) adsorption due to increased number of adsorption sites. Freundlich model fitted the experimental data better than Langmuir model. Adsorption process was found to be highly pH dependent. The optimum pH for adsorption of Ni(II) was found to be 7. Adsorption equilibrium attained within 1 h time. The sorption of Ni(II) increased with rise of temperature. The adsorption process was spontaneous (ΔG° ads <0) and endothermic (ΔH° ads >0), supporting also the chemisorption is the rate-determining step. © 2015 Balaban Desalination Publications. All rights reserved.
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    Electrochemical Determination of Hydrazine at Gold and Platinum Nanoparticles Modified Poly(L-Serine) Glassy Carbon Electrodes
    (Taylor and Francis Inc., 2016) Koçak S.; Altın A.; Koçak Ç.C.
    ABSTRACT: L-serine monomer was polymerized electrochemically on a glassy carbon electrode by cyclic voltammetry. After L-serine polymerization, gold and platinum metal nanoparticles were doped by electrochemical reduction on the surface. The modified electrodes were characterized by using scanning electron microscopy and electrochemical impedance spectroscopy. The electrochemical behavior of hydrazine oxidation at the electrodes was investigated in 0.1 M pH 7.0 phosphate buffer. Hydrazine oxidation peaks were observed at 650, 399, 280, and −395 mV at the bare glassy carbon, poly(L-serine) modified glassy carbon, gold nanoparticle modified poly(L-serine) film glassy carbon electrode, and platinum nanoparticles modified poly(L-serine) film glassy carbon electrode, respectively. The most active surface towards hydrazine oxidation was the platinum nanoparticle modified poly(L-serine) film glassy carbon electrode with a 1045 mV negative potential shift and approximately three-fold higher peak current. The hydrazine oxidation peak was shifted to a 370 mV negative potential with a 2.5 times higher current at the gold nanoparticle modified poly(L-serine) film glassy carbon electrode compared to the bare electrode. The linear concentration ranges were from 1.0 to 1000 µM and 0.5 to 1000 µM for the gold nanoparticle modified poly(L-serine) film glassy carbon and the platinum nanoparticles modified poly(L-serine) film glassy carbon electrodes with limits of detections of 0.5 and 0.2 µM, respectively. © 2016, Copyright © Taylor & Francis Group, LLC.
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    A new species and two new records of the genus Tycherobius Bolland (Acari: Camerobiidae) from Turkey
    (Taylor and Francis Inc., 2016) Ulucay I.; Koc K.; Akyol M.
    A new species of the genus Tycherobius anatolicus sp. nov. collected from soil and litter under Crataegus sp. and Juglans sp. in Turkey is described and illustrated based on adult females. Additionally, T. iranensis Khanjani, Yazyanpanah, Ostovan and Asali Fayaz 2012 and T. sahragardi Khanjani, Hajizadeh, Hoseini and Jalili 2013 are recorded for the first time in Turkey. A comparison of characters of adult females of the genus Tycherobius is given and a key to known species of Tycherobius is provided. © 2016 Taylor & Francis.
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    Determination of Hydrazine at a Platinum Nanoparticle and Poly(Bromocresol Purple) Modified Carbon Nanotube Electrode
    (Taylor and Francis Inc., 2016) Koçak S.; Aslışen B.; Koçak Ç.C.
    ABSTRACT: Bromocresol purple was polymerized electrochemically at a carbon nanotube modified glassy carbon electrode and platinum nanoparticles were doped on the polymer film by electrochemical reduction. The modified electrodes were characterized by electrochemical impedance spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The oxidation of hydrazine was investigated at the platinum nanoparticle modified electrode in phosphate buffer. The results were compared with those obtained using other modified and bare electrodes. The best catalytic activity was obtained at the platinum nanoparticle modified electrode due to shift of the oxidation peak to more negative values and highest current. The peak potential and current for hydrazine were −445 mV and 175.5 µA, respectively. Linear calibration curves for hydrazine were obtained from 10 to 1000 mM. The limits of detection and quantitation for hydrazine were 1.0 and 3.0 mM, respectively. © 2016, Copyright © Taylor & Francis Group, LLC.
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    Pyrene bisiminopyridine ligand and its zinc complex
    (Taylor and Francis Inc., 2016) Ayadi A.; Branzea D.; Dinçalp H.; Zouari N.; El-Ghayoury A.
    The synthesis of a pyrene bisiminopyridine ligand L was successfully accomplished by condensation between 1-aminopyrene and 2,6-pyridinecarboxaldehyde. The complexation of L with zinc triflate afforded a neutral metal complex formulated as [Zn(H2O)LCF3SO3)2].2Et2O. In the complex, the ligand is coordinated to zinc(II) through its three nitrogen atoms which form a distorted octahedral environment together with three oxygen atoms, two from the triflate anions and one from aqua ligand. Both compounds have been characterized using NMR, elemental analysis, mass spectrometry, electronic absorption (UV-Vis) and infrared. Luminescence properties of these compounds show an emission maxima at 412 nm, indicating a pyrene monomer emission. © 2016 Taylor & Francis Group, LLC.
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    Depolitization of Bureaucracy: The Case of Central and Eastern European Countries
    (Taylor and Francis Inc., 2017) Demir F.
    Political parties worldwide seek to work with bureaucrats who are close to their programs, willing to cooperate, and concerted. On the other hand, there is a huge body of literature which argues that bureaucracy should be separate from politics and that it has to consist of public servants who are technically knowledgeable, expert, and also politically neutral. The countries of Central and Eastern Europe suffered from highly politicized public administrations under one-party regimes, and have struggled to separate their bureaucracies from politics since early 1990s. In view of the relation between politics and bureaucracy from the perspective of (de)politization, this paper looks into the changes that Central and Eastern European countries (CEECs) have gone through after the institutionalization of multi-party regimes and tries to provide some generalizations. © 2016 Taylor & Francis.
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    Fatty acid composition, enzyme inhibitory, and antioxidant activities of the ethanol extracts of selected wild edible plants consumed as vegetables in the Aegean region of Turkey
    (Taylor and Francis Inc., 2017) Sarikurkcu C.; Targan S.; Ozer M.S.; Tepe B.
    The aim of this study was to evaluate the fatty acid composition, enzyme inhibitory, and antioxidant activities of the ethanol extracts of selected wild edible plants consumed as vegetable in the Aegean region of Turkey. In general, Mentha piperita L., Rumex patientia L., and R. acetosella L. exhibited quite strong antioxidant activities in the majority of test systems, whereas Urtica dioica L. and Eruca sativa Mill. show quite weak antioxidant activities. Enzyme inhibitory activities of the plants were found quite different than those of their antioxidant activities. Cardaria draba (L.) Desv., E. sativa, R. patientia, and E. cicutarium (L.) L’Hér. showed the highest inhibitory activities on acetylcholinesterase, butyrylcholinesterase, α-amylase, and α-glucosidase, respectively. U. dioica also showed a promising inhibitory activity on these enzymes. In parallel to the experiments, total phenolic, flavonoid, flavonol, and saponin contents of the extracts were also determined. According to the results of these assays, M. piperita had the highest amounts of phenolics, flavonols, and saponins (162.36 mg gallic acid equivalents/g extract, 3.52 mg CEs/g extract and 761.54 mg QAEs/g extract, respectively). Opopanax hispidus (Friv.) Griseb. and Lepidium sativum L. were found to be rich in flavonoid compounds (121.18 and 104.21 mg Res/g extract, respectively). In general, a strong correlation was determined between the phytochemical profile and antioxidant activity of the plant species. © 2017 Taylor & Francis Group, LLC.
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    Evaluating vendor managed inventory systems: how incentives can benefit supply chain partners
    (Taylor and Francis Inc., 2017) Birim S.; Sofyalioglu C.
    In a vendor managed inventory (VMI) system, the effects of financial incentives on the entire supply chain (SC) and on the individual firms are investigated in this study. To this end, order management, order replenishment and inventory control activities of a two-echelon SC are examined via modeling using discrete event simulation. By determining the appropriate parameters for the incentives with scenario analysis, balanced profit distribution between buyers and a supplier in VMI is established. Simulation outputs of the traditional model, VMI only and VMI with incentives models are compared based on profits with paired comparisons. In VMI with incentives, both buyers, and the supplier experience higher benefits than the traditional system. This study provides a new method which eliminates the unbalanced benefit distribution due to VMI and offers almost equal benefits to the participating firms. With financial incentives, firms are encouraged to share information with each other to work in a coordinated SC. © 2017 Vilnius Gediminas Technical University (VGTU) Press.