35 research outputs found
Contaminants in Animal Products
Organic and conventional animal products may include residues of veterinary drugs and environmental contaminant. Food contaminants can cause consumer illness such as allergy, immunosuppression, cancer, teratogenicity, mutagenicity and genotoxicity. Therefore, their control is an important issue in terms of public health. In this article, information is given about contaminants such as bacterial, fungal, metal pesticides and veterinary drug that can be found in organic and conventional animal products. In addition, the effects of various cooking and freezing processes on contaminants in animal foods and their legal regulation have been mentioned
Polipropilen iletken nanokompozitleri ve polietilen kapı dilektrikli organik alan etkili transistörler.
One of the aim of this study is to prepare conductive polymer nanocomposites of polypropylene to obtain better mechanical and electrical properties. Composite materials based on conductive fillers dispersed within insulating thermoplastic matrices have wide range of application. For this purpose, conductive polymer nanocomposites of polypropylene with nano dimentional conductive fillers like carbon black, carbon nanotube and fullerene were prepared. Their mechanical, electrical and thermal properties were investigated. Polypropylene (PP)/carbon black (CB) composites at different compositions were prepared via melt blending of PP with CB. The effect of CB content on mechanical and electrical properties was studied. Test samples were prepared by injection molding and compression molding techniques. Also, the effect of processing type on mechanical and electrical properties was investigated. Composites become semiconductive with the addition of 2 wt% CB. Polypropylene (PP) / Carbon Nanotube (CNT) and Polypropylene / Fullerene composites were prepared by melt mixing. CNT’s and fullerenes were surface functionalized with HNO3 : H2SO4 before composite preparation. The CNT and fullerene content in the composites were varied as 0.5, 1.0, 2.0 and 3.0 % by weight. For the composites which contain surface modified CNT and fullerene four different compatibilizers were used. These were selected as TritonX-100, Poly(ethylene-block-polyethylene glycol), Maleic anhydride grafted Polypropylene and Cetramium Bromide. The effect of surface functionalization and different compatibilizer on mechanical, thermal and electrical properties were investigated. Best value of these properties were observed for the composites which were prepared with maleic anhydride grafted polypropylene and cetramium bromide. Another aim of this study is to built and characterize transistors which have polyethylene as dielectric layers. While doing this, polyethylene layer was deposited on gate electrode using vacuum evaporation system. Fullerene , Pentacene ve Indigo were used as semiconductor layer. Transistors work with low voltage and high on/off ratio were built with Aluminum oxide - PE and PE dielectrics.Ph.D. - Doctoral Progra
Synthesis and Characterization of Surface Modified Fullerene
Fullerenes were chemically functionalized by using sulphuric acid and nitric acid. The functionalization was done with two different acid ratio. The functionalized nanotubes were characterized with Fourier transform infrared spectroscopy and X-ray photonelectron spectroscopy (XPS), elemental analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Sulfonation of fullerene increased the electrical conductivity of fullerenes up to 0.027 S/cm. TEM micrographs showed that sulfonation improves the dispersion of fullerene in water. Zeta potential measurements also proved this result
Electrical and Mechanical Properties of Polypropylene/Carbon Black Composites
Polypropylene(PP)/carbon black(CB) composites at different compositions were prepared via melt blending of PP with CB. The effect of CB content on mechanical and electrical properties was studied. Test samples were prepared by injection molding and compression molding techniques. The effect of processing type on mechanical and electrical properties was also investigated. Composites become semi-conductive by addition of 2wt% CB. The relation between mechanical and electrical properties was discussed. The influence of CB content on morphology and crystallinity was also studied
Surface Modification and Characterization of Multi-Walled Carbon Nanotube
Multi-walled carbon nanotubes (MWCNTs) were chemically functionalized by using sulfuric acid and nitric acid. The functionalization was done with two different acid ratio. The functionalized nanotubes were characterized with Fourier Transform Infrared Spectroscopy, X-Ray Photon Spectroscopy, Thermal Gravimetric Analysis, Elemental Analysis, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy. Sulfonation of carbon nanotubes (CN) increased the electrical conductivity of carbon nanotubes up to 1.25 x 10-1 S/cm. The SEM micrographs of the samples showed that CN was observed in more bulky form due to the increasing hyrogen bonding between the particles. The zeta potential of the CN increased with increasing sulfonation amount
Monensin induces apoptosis in the liver tissue and primary hepatocytes of chicks
In this study, monensin (MON) was investigated for its apoptotic and genotoxic effects on chick liver tissue and cytotoxic and apoptotic effects on chick primary hepatocytes isolated from perfused liver tissue. Western blotting and real-time PCR (qPCR) were used to determine the apoptotic effect on primary hepatocytes and liver tissue, and the comet assay was used to determine the genotoxic effect on liver tissue. MON decreased cell viability in primary hepatocytes with increasing concentrations. When administered at concentrations of 1 and 10 ??M, MON increased the levels of apoptotic p53, caspase-3, and caspase-9, and downregulated the expression of the antiapoptotic survivin, Bcl-xl, and Bcl-2 genes (p < 0.05). Furthermore, 100 and 125 ppm of MON increased caspase-3, caspase-9, and p53 protein levels, and downregulated Bcl-2 expression (p < 0.05). Bcl-xl gene expression was downregulated only in the group that received 125 ppm of MON (p 0.05). Changes observed in the expression of the survivin gene were insignificant in both groups (p 0.05). Moreover, 100 and 125 ppm of MON caused comet formation, which is a marker of genotoxicity, in the liver (p < 0.05). Our results indicate that MON induced apoptosis in both primary hepatocytes and liver tissue, and also caused genotoxicity in the liver tissue