RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A

This study aims to find out usage of zinc oxide (ZnO) and 2-hydroxy-4-methoxybenzophenone (BP-3) for getting better optical and structural properties of nanocomposites. Polymer nanocomposites were prepared by adding zinc oxide for minimizing UV rays effects of the sun with the particle size of nanometer in different ratios to a low density polyethylene (LDPE). The polymer mixtures were synthesized by mixing nanocomposite samples with BP-3 featuring UV stabilizer. Besides making tensile testing measurements, in order to find out the optical, structural, mechanical and thermal changes, the new polymer nanocomposites were characterized by XRD, TG-DTA spectra, and SEM images. The samples with zinc oxide which show luminescent properties were examined in terms of radioluminescence features. Radioluminescence spectrum showed characteristic peaks of zinc oxide dispersed nanocomposites prepared with LDPE. The intensity of the characteristic peaks at 530 and 390 nm (exciton) increased by increasing rates of nanopowder zinc oxide while adding BP-3 to the composites caused a decrease in intensity of radioluminescence

Analysis of sugars, organic acids and vitamin C contents of blackberry genotypes from Turkey

The paper reports the composition of some quality characteristics of five blackberry varieties ("C. Thornless", "Bursa 2", "Navaho", "Jumbo" and "Loch Ness"). Main soluble sugar and acid contents of experimental varieties were separated, identified and quantified using high-performance liquid chromatography with photo diode array spectrophotometric and refractive index detection, for organic acids, ascorbic acids and soluble sugars, respectively. According to the results, malic acid was detected as the main organic acid while citric acid was not detected in blackberry fruits. Ascorbic acid content was found very low quantity and also was not detected in all the cultivars. As for the sugars, fructose was found as the most abundant sugar and highly detected in "Navaho". However, the highest total sugar/malic acid ratio was found in cv. C. Thornless. (c) 2005 Elsevier Ltd. All rights reserved

Determination of aroma compounds in blackberry by GC/MS analysis

The aromatic composition of five blackberry cultivars (Bursa 2, Navaho, Nessy, Chester Thornless, and Jumbo) was studied. The Im-SPME (Immersion Solid Phase Micro Extraction) extraction technique was applied and the samples were analyzed by GC/MS. Furfural and its derivatives were found to be the major aromatic compounds and 5-hydroxymethyl furfural was the most abundant compound in all the blackberry varieties

Fruit quality characteristics of organically grown strawberries

Strawberries are moderately amenable to organic production. Recently organically strawberry cultivation has become important due the having less residual pesticides compared the conventional fruits. In this study, it was aimed to identify and quantify individual sugars such as fructose, glucose and sucrose, carboxylic acids such as malic and citric acid and L-ascorbic acid using HPLC (high performance liquid chromatography) techniques. Total anthocyanin and antioxidant capacity of organically cultivated 'Albion' and 'Benicia' strawberry fruits were also compared

Microstructure and Electrical Conductivity of ZnO Addition on the Properties of (Bi0.92Ho0.03Er0.05)(2)O-3

The solid electrolyte is one of the most important components for a solid oxide fuel cell (SOFC). The various divalent or trivalent metal ion-doped bismuth-based materials exhibit good ionic conductivity. Therefore, these materials are used as electrolytes in the SOFC. In this paper, the samples of (Bi0.92-x Ho0.03Er0.05)(2)O-3 + (ZnO) (x) solutions with a 0 aecurrency sign x aecurrency sign 0.2 molar ratio are synthesized by the solid state reaction method. The detailed structural and electrical characterizations are investigated by using x-ray diffraction (XRD), alternating current electrochemical impedance spectroscopy, and scanning electron microscopy (SEM). The XRD patterns of all samples are indexed on a monoclinic symmetry with a P2(1)/c space group. In addition, the rietveld parameters are determined by using the FullProf software program. The impedance measurements of the samples are obtained at the 1 Hz to 20 MHz frequency range. The impedance value of the pellets increases with temperature. Based on the impedance results, it is found that the contribution of grain (bulk) is more than a grain boundary in terms of conductivity, which permits the attribution of a grain boundary. The ionic conductivity decreases with an increasing amount of Zn contribution. The value of highest electrical conductivity among all samples is calculated as 0.358 S cm(-1) at 800A degrees C for undoped (Bi0.92Ho0.03Er0.05)(2)O-3

Optimizing Optical and Structural Properties of Nanocomposites by ZnO and BP-3

WOS: 000443988100019This study aims to find out usage of zinc oxide (ZnO) and 2-hydroxy-4-methoxybenzophenone (BP-3) for getting better optical and structural properties of nanocomposites. Polymer nanocomposites were prepared by adding zinc oxide for minimizing UV rays effects of the sun with the particle size of nanometer in different ratios to a low density polyethylene (LDPE). The polymer mixtures were synthesized by mixing nanocomposite samples with BP-3 featuring UV stabilizer. Besides making tensile testing measurements, in order to find out the optical, structural, mechanical and thermal changes, the new polymer nanocomposites were characterized by XRD, TG-DTA spectra, and SEM images. The samples with zinc oxide which show luminescent properties were examined in terms of radioluminescence features. Radioluminescence spectrum showed characteristic peaks of zinc oxide dispersed nanocomposites prepared with LDPE. The intensity of the characteristic peaks at 530 and 390 nm (exciton) increased by increasing rates of nanopowder zinc oxide while adding BP-3 to the composites caused a decrease in intensity of radioluminescence

Performance Analysis for Steady Flow Generation and Improved Readout Signal in Amperometric Biosensors

The use of peristaltic pumps as fluidic distribution microsystems in electrochemical biosensor devices operating with amperometric transducers can result in periodic spikes affecting the output signal. Mechanical components rotating inside the pumps are the main cause of this kind of disturbing noise. A novel fluidic setup based on simple fluid mechanics laws has been realized with no moving components when pump is on. It yields a fluctuation-free outcome signal that we compare with those produced by commercial peristaltic pumps. Evidence of the readout amperometric enhanced signal is shown thus confirming the successful implementation of more reliable biosensors and electrochemical signal transduction devices. Such stable and oscillation free amperometric signals are very desirable in view of biosensors integration in environmental monitoring platforms equipped with advanced communication technologies. An example is reported for their use in data mining systems equipped with a remote control for the real-time monitoring of pollutants. The cleanliness and the strength of the signal can adversely affect the reliability of the transmission of relevant information, especially when there are early warning civil purposes referred to a potential harmful contamination (i.e., water bodies pollution)

Microstructure and Electrical Conductivity of ZnO Addition on the Properties of (Bi0.92Ho0.03Er0.05)(2)O-3

The solid electrolyte is one of the most important components for a solid oxide fuel cell (SOFC). The various divalent or trivalent metal ion-doped bismuth-based materials exhibit good ionic conductivity. Therefore, these materials are used as electrolytes in the SOFC. In this paper, the samples of (Bi0.92-x Ho0.03Er0.05)(2)O-3 + (ZnO) (x) solutions with a 0 aecurrency sign x aecurrency sign 0.2 molar ratio are synthesized by the solid state reaction method. The detailed structural and electrical characterizations are investigated by using x-ray diffraction (XRD), alternating current electrochemical impedance spectroscopy, and scanning electron microscopy (SEM). The XRD patterns of all samples are indexed on a monoclinic symmetry with a P2(1)/c space group. In addition, the rietveld parameters are determined by using the FullProf software program. The impedance measurements of the samples are obtained at the 1 Hz to 20 MHz frequency range. The impedance value of the pellets increases with temperature. Based on the impedance results, it is found that the contribution of grain (bulk) is more than a grain boundary in terms of conductivity, which permits the attribution of a grain boundary. The ionic conductivity decreases with an increasing amount of Zn contribution. The value of highest electrical conductivity among all samples is calculated as 0.358 S cm(-1) at 800A degrees C for undoped (Bi0.92Ho0.03Er0.05)(2)O-3

Structural, optical, luminescence properties and energy transfer mechanism of Tb3+/Eu(3+)co-doped SrLa2(MoO4)(4) phosphors produced by sol-gel process

Tb3+/Eu3+ co-doped SrLa2(MoO4)(4) have been synthesized using the sol-gel process. The as-produced light-emitting phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA)/thermogravimetric analysis (TG), optical absorption spectra, radioluminescence (RL), and photoluminescence (PL) spectra. The effect of Tb(3+)and Eu(3+)doping concentrations on the RL and PL intensity of host material was analyzed in details. Furthermore, the energy transfer mechanism based on RL spectra were determined of Tb3+/Eu(3+)co-doped SrLa2(MoO4)(4) phosphors. When the samples excited by X-ray, the SrLa2(MoO4)(4) phosphors exhibit characteristic emissions of Tb3+ (489, 544, 586, 620 and 675 nm) and Eu(3+)d (545, 592, 614, 650 and 700 nm). Also, similar emissions are observed in the results of PL spectra, when the samples excited by 488 nm. The host material has excellent energy transfer efficiency for lanthanide ions. In addition, the luminescence spectra indicated that the energy transfer is also effective between from Tb3+ to Eu(3+)and vice versa. The CIE parameters are calculated to characterize the color emission. Under UV excitation, the synthesized materials display different color from green to red. Based on the results, the SrLa2(MoO4)(4:Eu)(3+)(3+)(,Tb) phosphors may be potential candidates for light-emitting diode. (C) 2019 Elsevier B.V. All rights reserved