Multiwall-carbon nanotube/cobalt ferrite hybrid: Synthesis, magnetic and conductivity characterization

B. Unal,M. Senel,A. Baykal,H. Sözeri 한국물리학회 2013 Current Applied Physics Vol.13 No.7

Functionalized multiwall carbon nanotubes (MWCNT-COOH) were decorated with crystalline cobalt ferrite nanoparticles (CoFe2O4 NPs) by co-precipitation reaction to form MWCNT-COOH/CoFe2O4 hybrid. The hybrid was characterized by X-ray diffraction analysis, transmission electron microscopy (TEM),Fourier transfom infrared spectroscopy and vibrating sample magnetometry. The results confirmed that MWCNTs and CoFe2O4 NPs coexisted in the hybrid. The TEM results showed a thick layer of CoFe2O4 was intimately connected to the surface of MWCNTs. The saturation magnetization value of the hybrid was 11.5 emu/g. There has been a high frequency fluctuation in conductivity, however, above all dc conductivity changes and resulting activation energy is calculated from the Arrhenius plots. It is found to vary with the temperature regions. This can be attributed to the existence of a conventional temperature independent tunneling conduction mechanism, which can be also explained that the metallic conduction is a dominant mechanism around room temperature. The ac conductivity of MWCNT-COOH/CoFe2O4hybrid might also be a consequence of the predictions of the universal dynamic response and the ‘n’power exponents could be determined with lower concentration of the addition in the hybrids.

Poly(glycidylmethacrylate-co-vinyl ferrocene)-grafted iron oxide nanoparticles as an electron transfer mediator for amperometric phenol detection

Emre Çevik,Mehmet S¸ enel,Abdulhadi Baykal,M. Fatih Abasıyanık 한국물리학회 2013 Current Applied Physics Vol.13 No.8

An amperometric phenol biosensor was constructed by using poly(glycidylmethacrylate-co-vinyl ferrocene) grafted iron oxide nanoparticles for detection of different phenolic compounds (catechol, aminophenol, phenol, p-cresol, pyrogallol). The poly(glycidylmethacrylate-co-vinyl ferrocene) and nanoparticles were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The copolymer grafted iron oxide nanoparticles and Horseradish peroxidase (HRP) were covalently attached on gold (Au) electrode surface. The effect of pH, temperature and characteristic features such as; reusability and storage stability were studied. The electrode showed good response time within w3 s. The electrocatalytic response showed a linear dependence on the phenolic compounds concentration ranging from 0.5 to 17.0 mM.

Potentiometric urea biosensor based on poly(glycidylmethacrylate)-grafted iron oxide nanoparticles

Emre Çevik,Mehmet S¸ enel,Abdülhadi Baykal 한국물리학회 2013 Current Applied Physics Vol.13 No.1

Urease enzyme was covalently attached on the poly(glycidylmethacrylate) (PGMA)-grafted iron oxide nanoparticles on Au electrode for the fabrication of urea biosensor. The telomere of poly(- glycidylmethacrylate) (PGMA) with a trimethoxysilyl terminal group was synthesized by telomerization of glycidylmethacrylate. Iron oxide nanoparticles were coated with telomere of poly(- glycidylmethacrylate) in order to obtain good enzyme immobilization platform. The telomere and nanoparticles were characterized by using Fourier transform infrared (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The biosensor’s potentiometric response was measured as a function of urea concentration in phosphate buffer solution (10 mM, pH 7.5) and showed a linear range of 0.25e5.0 mM urea. The produced biosensor exhibited a good response time of w8 s and was stable for about two months. The basic features (optimum pH, optimum temperature, interference and storage stability) of the enzyme electrode were determined

Effects of Saccharomyces cerevisiae Supplementation and Anhydrous Ammonia Treatment of Wheat Straw on In-situ Degradability and, Rumen Fermentation and Growth Performance of Yearling Lambs

Comert, Muazzez,Sayan, Yilmaz,Ozelcam, Hulya,Baykal, Gulsah Yegenoglu Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.5

The effects of Saccharomyces cerevisiae supplementation ($6.6{\times}10^8cfu$) and anhydrous ammonia treatment (3%) of wheat straw (WS) were investigated on in-situ dry matter (DM) degradability, and on rumen fermentation and growth performance of lambs. Rumen-fistulated Menemen sheep fed a diet with and without live yeast were used to assess the DM degradability characteristics of WS and ammonia-treated wheat straw ($WS_{NH3}$). Twenty-six yearling Menemen male lambs were fed in four groups. Lambs of control group (WS) received untreated WS without supplemental yeast, whereas other three groups were fed WS treated with anhydrous ammonia ($WS_{NH3}$ group), untreated WS and yeast (WS+YEAST group) or WS treated with anhydrous ammonia and yeast ($WS_{NH3}$+YEAST group). Supplemented live yeast (4 g/d) was added in the diet. Lambs were offered untreated or ammonia treated WS ad-libitum and concentrate was fed at 1% of live body weight. The degradability of the water-insoluble (fraction B) was significantly increased by all of the treatment groups. Potential degradability (A+B), effective DM degradability's (pe2, pe5, and pe8) and average daily weight gain increased only in $WS_{NH3}$+YEAST group (p<0.05). Voluntary DM intake was not increased by the treatments (p>0.05), but voluntary metabolizable energy and crude protein intake were increased by $WS_{NH3}$ and by $WS_{NH3}$+YEAST (p<0.05). Average daily rumen pH was not affected by any of the treatments, but average daily $NH_3$-N was significantly higher in the $WS_{NH3}$ and $WS_{NH3}$+YEAST groups, and total volatile fatty acids were significantly higher in the WS+YEAST and $WS_{NH3}$+YEAST groups. In conclusion, the improvement of feed value of WS was better by the combination of ammonia-treatment and yeast supplementation compared to either treatment alone.

Rapid color degradation of organic dyes by Fe3O4@His@Ag recyclable magnetic nanocatalyst

Md. Amir,U. Kurtan,A. Baykal 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.27 No.-

In this study, we reported the degradation of organic dyes (methyl orange, MO and methylene blue, MB)by Fe3O4@His@Ag MRC in which histidine was used as linker. The size of crystallite of MRC wascalculated as 19 nm. The M–H hysteresis loop of the product indicates that it exhibits superparamagneticproperty at room temperature. Catalytic studies showed that this product could catalyze the degradationof MO and MB in a reasonable time. Moreover, the product can be recycled five times by magneticseparation without major loss of its activity. Thus, Fe3O4@His@Ag MRC can be served as an effective andconvenient recyclable nanocatalyst for azo dye degradation and hence as an environmental protectionapplication too.

CASE REPORT : Two Clinically Unusual Cases of Folliculotropic Mycosis Fungoides: One with and the Other without Syringotropism

( Ozgur Bakar ),( Dilek Seckin ),( Cuyan Demirkesen ),( Can Baykal ),( Nesimi Buyukbabani ) 대한피부과학회 2014 Annals of Dermatology Vol.26 No.3

Mycosis fungoides is the most common form of cutaneous T-cell lymphoma, and it rarely exhibits predilection for hair follicle and eccrine gland infiltration. Here, we present 2 similar cases that display folliculotropism with varying amounts of follicular mucinosis, with and without syringotropism. The features observed in both cases were cystic, comedo-like, acneiform lesions; generalized involvement with loss of body hair; pruritus; and hidradenitis suppurativa- like lesions. Hypohidrosis as well as nail and palmoplantar involvement with lichen planopilaris-like clinical features were unique characteristics of the first case. Despite the well-known aggressive behavior of follicular mycosis fungoides, the presented cases had a subtle, slowly progressive, but persistent, clinical course. Folliculotropic and syringotropic mycosis fungoides are variants of cutaneous T-cell lymphoma. Clinical presentations might be challenging, and multiple, deep biopsy specimens containing adnexal structures are required for this critical diagnosis. Aggressive treatment may not be necessary in cases having an indolent course, especially in those with syringotropism. (Ann Dermatol 26(3) 385∼391, 2014)

Is the Loop Electrosurgical Excision Procedure Necessary for Minor Cervical Cytological Abnormalities?

Aksan-Desteli, Guldeniz,Gursu, Turkan,Baykal, Cem Murat Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Background: To investigate the indications of loop electrosurgical excision procedure (LEEP) and its overtreatment rates for the see and treat and three step strategies in cases of atypical squamous cells of undetermined cytology (ASC-US) and low grade intraepithelial neoplasia (LGSIL) cytology. Materials and Methods: We retrospectively analyzed colposcopy directed biopsy (CDB) and LEEP results of 176 paients with ASC-US or LGSIL cytologies who underwent colposcopic examination. Results: Initial cytologies were ASCUS in 120 women and LGSIL in 56. According to the see and treat approach immediate LEEP was performed for38 women. Among the remaining 138 women, LEEP was performed for 32 whose CDB results revealed CIN2/3 lesions. In the see and treat group the recognition of CIN2/3 was found to be 39.4%. The overtreatment rate was 60% as compared to 25% in the three step group. In CDB group detection of CIN 2 or greater lesions increased with 3 or more biopsies. Conclusions: In patients with ASC-US/LGSIL cytologies CDB should be performed before LEEP to prevent overtreatment, with attention to all suspected areas and more than 2 biopsies taken.

Dielectric and proton conductivity studies in organic electrolytes based on 2-perfluoroalkyl-ethyl-azides

Sedat Cos gun,Sevim Ünügür Çelik,Abdulhadi Baykal,Ayhan Bozkurt 한국물리학회 2010 Current Applied Physics Vol.10 No.1

Intrinsically proton conducting organic electrolytes based on 2-perfluoroalkyl-ethyl-azides were synthesized via 1,3 cycloaddition between 2-perfluoroalkyl-ethyl-azide and alkynes. FT-IR, elemental analysis and NMR methods were used to characterize the resulting organic electrolytes. Thermal properties were analyzed with thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and the morphology of the organic electrolytes was studied with X-ray diffraction (XRD). The effect of chain length on proton conductivity was investigated with impedance spectrometer. Dielectric constant and electrical modulus formalisms were analyzed and the maximum proton conductivity was measured as 10-2 mS/cm at 180 ℃.

Strong correlation between Dy3+ concentration, structure, magnetic and microwave properties of the [Ni0.5Co0.5](DyxFe2-x)O4 nanosized ferrites

M. A. Almessiere,Y. Slimani,A.V. Trukhanov,A. Baykal,H. Gungunes,E.L. Trukhanova,S.V. Trukhanov,V.G. Kostishin 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.90 No.-

The dysprosium ions (Dy3+)-substituted nanosized ferrites (NFs) of composition [Ni0.5Co0.5](DyxFe2-x)O4(x0.08) were prepared using the citrate gel process. To analyse the magnetic properties of the samples,the Mössbauer spectroscopy methods and vibrating sample magnetometry (VSM) were applied. Theroom temperature Mössbauer spectra werefitted to determine the hyperfine parameters of the proposedNFs. The preferential occupation of the octahedral B sites by the Dy3+ in the spinel ferrite sublattice wasconfirmed from the cations distribution. The hyperfine magneticfield of both sublattice decreasedwhereas the increase in the Dy3+ substitution was observed. The S-parameters of the prepared NFs in thehigh frequency range were measured by the co-axial method. In addition, the MW reflection losses wereevaluated by means of the frequency-dependent (in the range of 1–20 GHz) complex permittivity andpermeability spectra. All the NFs indicated that the absorption of the electromagnetic radiation wasranging between 2.9–5.5 GHz due to the natural ferromagnetic resonance. A correlation amongst the Dy3+ concentration, microstructure, magnetic and microwave (MW) characteristics of these NFs wasestablished. It’s been asserted that by controlling the Dy3+ contents carefully, the MW absorption andmagnetic attributes of the proposed spinel NFs can be tailored.

Effects of Saccharomyces cerevisiae Supplementation and Anhydrous Ammonia Treatment of Wheat Straw on In-situ Degradability and, Rumen Fermentation and Growth Performance of Yearling Lambs

Muazzez Comert,Yilmaz Sayan,Hulya Ozelcam,Gulsah Yegenoglu Baykal 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.5

The effects of Saccharomyces cerevisiae supplementation (6.6×108 cfu) and anhydrous ammonia treatment (3%) of wheat straw (WS) were investigated on in-situ dry matter (DM) degradability, and on rumen fermentation and growth performance of lambs. Rumen-fistulated Menemen sheep fed a diet with and without live yeast were used to assess the DM degradability characteristics of WS and ammonia-treated wheat straw (WSNH3). Twenty-six yearling Menemen male lambs were fed in four groups. Lambs of control group (WS) received untreated WS without supplemental yeast, whereas other three groups were fed WS treated with anhydrous ammonia (WSNH3 group), untreated WS and yeast (WS+YEAST group) or WS treated with anhydrous ammonia and yeast (WSNH3+YEAST group). Supplemented live yeast (4 g/d) was added in the diet. Lambs were offered untreated or ammonia treated WS ad-libitum and concentrate was fed at 1% of live body weight. The degradability of the water-insoluble (fraction B) was significantly increased by all of the treatment groups. Potential degradability (A+B), effective DM degradability’s (pe2, pe5, and pe8) and average daily weight gain increased only in WSNH3+YEAST group (p<0.05). Voluntary DM intake was not increased by the treatments (p>0.05), but voluntary metabolizable energy and crude protein intake were increased by WSNH3 and by WSNH3+YEAST (p<0.05). Average daily rumen pH was not affected by any of the treatments, but average daily NH3-N was significantly higher in the WSNH3 and WSNH3+YEAST groups, and total volatile fatty acids were significantly higher in the WS+YEAST and WSNH3+YEAST groups. In conclusion, the improvement of feed value of WS was better by the combination of ammonia-treatment and yeast supplementation compared to either treatment alone.