scholarly journals DEGRADATION OF AQUEOUS RHODAMINE B BY CATALYSIS ZONE EXTENSION OF MODIFIED DYES SENSITIZED SOLAR CELL.

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Wirya Sarwana

A modified dyes sensitized solar cell (DSSC) having catalysis zone have been successfully developed. The modified DSSC comprise of DSSC zone, employing a rhodamine B as the sensitizer, and catalysis zone, a simple an extension of the TiO2 nanotube film support which was not covered by dyes. The TiO2 nanotube was prepared by rapid breakdown anodization (RBA) method followed by heating treatment of obtained amorphous TiO2 nanotube, and charactetization by UV-Vis DRS, XRD, and SEM. Briefly, the obtained TiO2 has a bundling nanotube morphology, crystalline phase and typical band gap of anatase and rutile mixture (depend on heating temperature). The catalysis zone was tested to treat a water sample containing organic chemical (rhodamine B), as a pollutant model. Test results indicated that the catalysis zone enable to eliminate of rhodamine in the treated water, due to subsequent process starting by generation of super oxide (.O2-) in adjacent TiO2 surface, leading to hydroxyl radical which in turn degrade the rhodamine B. This result indicate that the injected electron from dyes, upon visible light absorption, to conduction band of TiO2 in DSSC zone was successfully migrated to TiO2 surface in catalysis zone.

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1419
Author(s):  
Tao Yang ◽  
Pei Wang ◽  
Qin Zhou ◽  
Xiao Wang ◽  
Jian Cai ◽  
...  

The behaviors of starch and protein in wheat flour during heating were investigated, and the molecular changes of starch and protein and their effects on the textural characteristics were assessed. The results showed that with the increased temperature, soluble protein aggregated to insoluble high-molecular-weight protein polymers when the heating temperature exceeded 70 °C, and the aggregation of protein was mainly caused by covalent bonds of disulfide (SS) bonds. Hydrophobic interaction was the main noncovalent bond that participated in the formation of protein aggregates. The major change in the secondary structure during heating was a pronounced transition towards β-sheet-like structures. Considerable disruption of ordered structures of starch occurred at 70 °C, and starch was fully gelatinized at 80 °C. Typical starch pasting profiles of cooked flour were observed when the temperature was below 70 °C, and heat treatment decreased the pasting viscosity of the cooked flour from control to 80 °C, whereas the viscosity of the wheat flour increased in heating treatment at 90, 95 and 100 °C. The intense protein-starch interaction during heating affected the textural characteristic of flour gelation, which showed higher strength at 90, 95 and 100 °C. This study may provide a basis for improving wheat flour processing conditions and could lead to the production of new wheat products.


2010 ◽  
Vol 168-170 ◽  
pp. 564-569
Author(s):  
Guang Lin Yuan ◽  
Jing Wei Zhang ◽  
Jian Wen Chen ◽  
Dan Yu Zhu

This paper makes an experimental study of mechanical properties of high-strength pumpcrete under fire, and the effects of heating rate, heating temperature and cooling mode on the residual compressive strength(RCS) of high-strength pumpcrete are investigated. The results show that under air cooling, the strength deterioration speed of high-strength concrete after high temperature increases with the increase of concrete strength grade. Also, the higher heating temperature is, the lower residual compressive strength value is. At the same heating rate (10°C/min), the residual compressive strength of C45 concrete after water cooling is a little higher than that after air cooling; but the test results are just the opposite for C55 and C65 concrete. The strength deterioration speed of high-strength concrete after high temperature increases with the increase of heating rate, but not in proportion. And when the heating temperature rises up between 200°C and 500°C, heating rate has the most remarkable effect on the residual compressive strength of concrete. These test results provide scientific proofs for further evaluation and analysis of mechanical properties of reinforced-concrete after exposure to high temperatures.


Nafta-Gaz ◽  
2021 ◽  
Vol 77 (2) ◽  
pp. 82-91
Author(s):  
Katarzyna Wojtowicz ◽  

The article presents the issues related to the determination of colored fluorescent tracers such as fluorescein, eosin yellowish, rhodamine B and uranine in reservoir waters by spectrophotometric method. For this purpose, the influence of the pH of the solution on the absorption spectra of the tested tracers was checked. Test results show that fluorescein, rhodamine B and uranine are sensitive to changes in the buffer pH, therefore it is advisable to use stable tracer solutions as well as to control and possibly correct pH in further tests. As part of the study, calibration curves of fluorescein, eosin yellowish, rhodamine B and uranine in distilled water, reservoir water A4 and highly sulfated reservoir waters A5 and A6 were plotted and the analytical methods were validated. Analytical validation included determination of linearity, standard deviation and relative standard deviation of the tested tracers solutions. High values of the regression parameters (0.9927–0.9998) of the analyzed tracers prove a good linear fit, while low values of standard deviation and relative standard deviation prove its repeatability and precision. Particular attention was paid to testing the stability of colored fluorescent tracers in highly sulfated reservoir waters. For this purpose, solutions of the tested tracers were prepared at concentrations of 10 mg/dm3 in distilled water, A4 reservoir water and highly sulfated A5 and A6 reservoir waters. Measurements of the tested tracers in the prepared solutions were performed every 2 days over the period of 1 month. The test results show that fluorescein, eosin yellowish, rhodamine B and uranine solutions are stable in the distilled water and A4 reservoir water, while they degrade in the A5 and A6 reservoir waters. Fluorescein and uranine turned out to be the most sensitive, as they degraded completely in the A6 reservoir water after 20 (fluorescein) and 22 (uranine) days. Yellowish eosin and rhodamine B turned out to be slightly more stable in highly sulfated reservoir waters, as they degraded completely in the A6 reservoir water after 24 days.


2014 ◽  
pp. 667-689
Author(s):  
Wentao Hu ◽  
Yongjun Tian ◽  
Zhongyuan Liu

The starting nanopowders of non-stoichiometric zirconium carbide (ZrCx) were fabricated via milling Zr powders in toluene for different dwell times. The carbon content was determined to depend on the milling time and the used amount of toluene. The bulk non-stoichiometric ZrCx with different x were prepared by spark plasma sintering of the obtained ZrCx nanopowders. The microstructural features of a sintered ZrC0.6 sample were investigated via the measurements of XRD, TEM, and HRTEM. It was found that the carbon vacancies have an ordering arrangement in C sublattice, forming a Zr2C-type cubic superstructural phase with space group of . Moreover, it was observed that the superstructural phase exists in nano-domains with an average size of ~30 nm owing to the ordering length in nanoscale. During the heating treatment in air, it was recognized that the diffusion of oxygen atoms is significantly facilitated through the ordered carbon vacancies. For the heating treatment at low temperature (<300°C), the oxygen atoms diffuse easily into and occupy the ordered carbon vacancies, forming the oxy-carbide of ZrC0.6O0.4 with ordered oxygen atoms. At the heating temperature higher than 350°C an amorphous layer of ZrC0.6Oy>0.4 was identified to be formed due to the diffusion of superfluous oxygen atoms into Zr-tetrahedral centers. Inside the amorphous layer, the metastable tetragonal zirconia nanocrystals are recognized to be gradually developed.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Seung Ki Baek ◽  
Ki Ryong Lee ◽  
Hyung Koun Cho

Oxide p-n heterojunction devices consisting of p-Cu2O/n-ZnO nanowires were fabricated on ITO/glass substrates and their photovoltaic performances were investigated. The vertically arrayed ZnO nanowires were grown by metal organic chemical vapor deposition, which was followed by the electrodeposition of the p-type Cu2O layer. Prior to the fabrication of solar cells, the effect of bath pH on properties of the absorber layers was studied to determine the optimal condition of the Cu2O electrodeposition process. With the constant pH 11 solution, the Cu2O layer preferred the (111) orientation, which gave low electrical resistivity and high optical absorption. The Cu2O (pH 11)/ZnO nanowire-based solar cell exhibited a higher conversion efficiency of 0.27% than the planar structure solar cell (0.13%), because of the effective charge collection in the long wavelength region and because of the enhanced junction area.


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