Fabrication and characterization of boron doped BaZrO3 nanofibers via an electrospinning technique

T. Tunç,I. Uslu,S. Keskin 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.5

In this study, boron doped and undoped poly(vinyl) alcohol/zirconium-barium acetate (PVA/Zr-Ba) nanofibers were prepared using an electrospinning technique then calcinated at three different temperatures; 250 oC, 500 oC, 800 oC for 2 h. The originality of this study is the addition of boron to metal acetates. The fibers were characterized by FT-IR, DSC, XRD and SEM. The addition of boron did not only increase the thermal stability of the fibers, but also increased their diameters, which gave stronger fibers. The FT-IR spectra of the fibers were in good accordance with literature data. The DSC results indicate that the glass transition (Tg) and melting temperatures (Tm) showed a change with the addition of boron. Also, boron doped fibers were observed to degrade at higher temperatures. XRD analyses showed that after further heat treatment at 800 oC,zirconia exists in two phases of tetragonal and monoclinic modifications. The systematic evolution of morphological features in the spun and the processed fibers were studied by scanning electron microscopy. The SEM appearance of the fibers showed that the addition of boron resulted in the formation of cross linked bright surfaced fibers.

QS-21 enhances the early antibody response to oil adjuvant foot-and-mouth disease vaccine in cattle

Can Çokçalışkan,Tunçer Türkoğlu,Beyhan Sareyyüpoğlu,Ergün Uzunlu,Ayca Babak,Banu B. Özbilge,Veli Gülyaz 대한백신학회 2016 Clinical and Experimental Vaccine Research Vol.5 No.2

Purpose: One of the most important tools against foot-and-mouth disease, a highly contagious and variable viral disease of cloven-hoofed animals, is vaccination. However, the effectiveness of foot-and-mouth disease vaccines on slowing the spread of the disease is questionable. In contrast, high potency vaccines providing early protection may solve issues with the spread of the disease, escaping mutants, and persistency. To increase the potency of the vaccine, additives such as saponin and aluminium hydroxide are used. However, the use of saponin with an oil adjuvant is not common and is sometimes linked to toxicity. QS-21, which is less toxic than Quil A, has been presented as an alternative for use with saponin. In this study, the addition of QS-21 to a commercially available foot-and-mouth disease water-in-oil-in-water emulsion vaccine was evaluated in cattle. Materials and Methods: After vaccination, serum samples were collected periodically over 3 months. Sera of the QS-21 and normal oil vaccine groups were compared via serum virus neutralization antibody titre and liquid phase blocking enzyme-linked immunosorbent assay antibody titre. Results: The results showed that there was a significant early antibody increase in the QS-21 group. Conclusion: Strong early virus neutralizing antibody response will be useful for emergency or ring vaccinations against foot-and-mouth disease in target animals.

The effect of PVA (Bi2O3-doped) interfacial layer and series resistance on electrical characteristics of Au/n-Si (110) Schottky barrier diodes (SBDs)

M. Gökçen,T. Tunç,Ş. Altındal,İ. Uslu 한국물리학회 2012 Current Applied Physics Vol.12 No.2

Two types of Schottky Barrier Diodes (SBDs) with and without PVA (Bi2O3-doped) polymeric interfacial layer, were fabricated and measured at room temperature in order to investigate the effects of the PVA (Bi2O3-doped) interfacial layer on the main electrical parameters such as the ideality factor (n), zero-bias barrier height (FB0), series resistance (Rs) and interface-state density (Nss). Electrical parameters of these two diodes were calculated from the currentevoltage (IeV) characteristics and compared with each other. The values of FB0, n and Rs for SBDs without polymeric interfacial layer are 0.71 eV, 1.44 and 4775 U, respectively. The values of FB0, n and Rs for SBDs with PVA (Bi2O3-doped) polymeric interfacial layer are 0.74 eV, 3.49 and 10,030 U, respectively. For two SBDs, the energy density distribution profiles of interface states (Nss) were obtained from forward-bias IeV measurements by taking the bias dependence of Rs of these devices into account. The values of Nss obtained for the SBD with PVA (Bi2O3-doped)polymeric interfacial layer are smaller than those of the SBD without polymeric interfacial layer.

Electrochemical synthesis and corrosion behaviour of poly (pyrrole-co-o-anisidine-co-o-toluidine)

Süleyman Yalçınkaya,Tunç Tüken,Birgül Yazıcı,Mehmet Erbil 한국물리학회 2010 Current Applied Physics Vol.10 No.3

In this study, a ter-polymer film of pyrrole, o-anisidine and o-toluidine has been electrochemically synthesized on low carbon steel. The synthesis solution was aqueous oxalic acid containing 2:1:1 monomer feed ratio between pyrrole, o-anisidine and o-toluidine, respectively. The characterization of synthesized ter-polymer film was realized with help of UV–Vis absorption, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) techniques. The stability of this ter-polymer film as a coating material has also been investigated on steel, in 3.5%NaCl solution. Under such severe conditions, the ter-polymer film was found to exhibit low permeability against water ingress. It was able to exhibit protective coating behavior on steel, even after 72 h exposure time. The DSC results revealed that the ter-polymer film had better thermal stability with respect to single polypyrrole film. The synthesized ter-polymer film was completely different in aspect of morphology,stability and other structural properties when compared to single polypyrrole film. This highly stable and extremely thin (0.80 ㎛) film can find application for various purposes (anticorrosive, electrocatalytic,etc.), at where the stability of polypyrrole like films constitutes a drawback.

Influence of vaccine potency and booster administration of foot-and-mouth disease vaccines on the antibody response in calves with maternal antibodies

Can Çokçalışkan,Tunçer Türkoğlu,Ergün Uzunlu,Beyhan Sareyyüpoğlu,İbrahim Hancı,Ahmet İpek,Abdullah Arslan,Ayca Babak,Gülnur İldeniz,Veli Gülyaz 대한수의학회 2017 Journal of Veterinary Science Vol.18 No.-

Foot-and-mouth disease is one of the most important viral diseases of cloven-hoofed animals. Mass vaccination is an effective method to control the disease and is frequently utilized in endemic regions. Sufficient protection of young animals is important in mass vaccination campaigns. Maternal antibodies negatively affect the success of vaccination. Hence, determination of the optimal vaccination age is crucial for the uninterrupted protection of young animals. This study was performed to identify the effect of vaccine potency and booster administration on serum neutralizing antibody titers of calves with different levels of maternal antibodies. Calves (n = 111) on a state farm were used in this study. Oil adjuvant foot-and-mouth disease vaccines with 3 PD50 and 6 PD50 potencies were used with or without booster administration. Serum samples were collected each month up to day 120 postvaccination. Virus neutralization tests were used to measure the serum neutralizing antibody titers and estimate the protection period by using pre-determined cut-off values for protection. The results revealed that a vaccination with a 6 PD50 potency vaccine, preferably followed by a booster dose, should be used to overcome maternal immunity for incessant protection.

Effect of simultaneous administration of foot-and-mouth disease (FMD) and anthrax vaccines on antibody response to FMD in sheep

Can Çokçalışkan,Pelin Tuncer Göktuna,Tunçer Türkoğlu,Ergün Uzunlu,Ceylan Gündüzalp,Eylem Aras Uzun,Beyhan Sareyyüpoğlu,Ayça Kürkçü,Veli Gülyaz 대한백신학회 2019 Clinical and Experimental Vaccine Research Vol.8 No.2

Purpose: Foot-and-mouth disease (FMD) and anthrax are important diseases in sheep. Vaccination is a favorable strategy against both infections. Simultaneous administration of vaccines does generally not impede the immune responses of each other, although there are some exceptions, and it may help reduce the labor and costs of vaccination as well as distress on animals. Although oil adjuvant FMD vaccine has been tried with live anthrax vaccine in cattle, there are no reports on the simultaneous use of both vaccines in sheep. Materials and Methods: In this study, FMD seronegative sheep were used to investigate the impact of the simultaneous vaccination of FMD and anthrax on FMD antibody titers of sheep. Virus neutralization test and liquid phase blocking enzyme-linked immunosorbent assay were used to determine the antibody response to the FMD vaccine. Results: The results demonstrated that both vaccines can be used simultaneously without any interference with the FMD response. Moreover, the simultaneous administration with anthrax vaccine had a stimulating effect on the early (day 7 post-vaccination) virus neutralization antibody response to the FMD vaccine. Conclusion: The simultaneous use of the FMD and anthrax vaccines did not hinder the response to the FMD vaccine in sheep.

Benzo-thia-fused [ <i>n</i> ]thienoacenequinodimethanes with small to moderate diradical characters: the role of pro-aromaticity <i>versus</i> anti-aromaticity

Shi, Xueliang,Quintero, Estefaní,a,Lee, Sangsu,Jing, Linzhi,Herng, Tun Seng,Zheng, Bin,Huang, Kuo-Wei,Ló,pez Navarrete, Juan T.,Ding, Jun,Kim, Dongho,Casado, Juan,Chi, Chunyan Royal Society of Chemistry 2016 Chemical Science Vol.7 No.5

<▼1><P>Pro-aromatic <B>Th<I>n</I>-TIPS</B> exhibits distinctly different physical properties from anti-aromatic <B>S<I>n</I>-TIPS</B>.</P></▼1><▼2><P>Open-shell singlet diradicaloids have recently received much attention due to their unique optical, electronic and magnetic properties and promising applications in materials science. Among various diradicaloids, quinoidal π-conjugated molecules have become the prevailing design. However, the need for a fundamental understanding on how the fusion mode and pro-aromaticity/anti-aromaticity affect their diradical character and physical properties remains unaddressed. In this work, a series of pro-aromatic benzo-thia-fused [<I>n</I>]thienoacenequinodimethanes (<B>Th<I>n</I>-TIPS</B> (<I>n</I> = 1–3) and <B>BDTh-TIPS</B>) were synthesized and compared with the previously reported anti-aromatic bisindeno-[<I>n</I>]thienoacenes (<B>S<I>n</I>-TIPS</B>, <I>n</I> = 1–4). The ground-state geometric and electronic structures of these new quinoidal molecules were systematically investigated by X-ray crystallographic analysis, variable temperature NMR, ESR, SQUID, Raman, and electronic absorption spectroscopy, assisted by DFT calculations. It was found that the diradical character index (<I>y</I><SUB>0</SUB>) increased from nearly zero for <B>Th1-TIPS</B> to 2.4% for <B>Th2-TIPS</B>, 18.2% for <B>Th3-TIPS</B>, and 38.2% for <B>BDTh-TIPS</B>, due to the enhanced aromatic stabilization. Consequently, with the extension of molecular size, the one-photon absorption spectra are gradually red-shifted, the two-photon absorption (TPA) cross section values increase, and the singlet excited state lifetimes decrease. By comparison with the corresponding anti-aromatic analogues <B>S<I>n</I>-TIPS</B> (<I>n</I> = 1–3), the pro-aromatic <B>Th<I>n</I>-TIPS</B> (<I>n</I> = 1–3) exhibit larger diradical character, longer singlet excited state lifetime and larger TPA cross section value. At the same time, they display distinctively different electronic absorption spectra and improved electrochemical amphotericity. Spectroelectrochemical studies revealed a good linear relationship between the optical energy gaps and the molecular length in the neutral, radical cationic and dicationic forms. Our research work discloses a significant difference between the pro-aromatic and anti-aromatic quinoidal compounds and provides guidance for the design of new diradicaloids with desirable properties.</P></▼2>