• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.433-438
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• 2011

In this study, CdS combined activated carbon/$TiO_2$ (CdS-AC/$TiO_2$) composites were prepared by a sol-gel method to improve the photocatalytic performance of $TiO_2$. These composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and UV-vis analysis. The photocatalytic activities were examined by the degradation of methylene blue (MB) under visible light irradiation. The photodegradation rate of MB under visible light irradiation reached 90.1% in 120 min. The kinetics of MB degradation was plotted alongside the values calculated from the Langmuir-Hinshelwood equation. The 0.2 CAT sample showed the best photocatalytic activity, which might be due to an increase in the photo-absorption effect by activated carbon and the cooperative effect of CdS.

• Nano
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• v.13 no.12
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• pp.1850142.1-1850142.9
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• 2018

Modified titanate nanotubes (TNT) were tested for their adsorption of methylene blue (MB) from water solutions. They were obtained from the $TiO_2$ nanopowder using a standard alkaline hydrothermal method but in the stage of acid washing, when the titanate flakes begin to roll into nanotubes, magnetite nanoparticles were added. The $Fe_3O_4$ magnetic nanoparticles with diameter of around 2 nm and 12 nm were used in the tests. Significantly stronger adsorption of MB was observed when smaller nanoparticles were used compared to using larger nanoparticles and compared to the case of unmodified nanotubes. It was shown that the increased adsorption of MB is associated with a more negative value of ${\zeta}$-potential for titanates modified by the ultra-small nanoparticles. In the adsorption experiment, pH 7 was selected. These results may prove to be of great importance in the case of potential applications corresponding to the use of such material for wastewater purification.

• Membrane and Water Treatment
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• v.10 no.2
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• pp.139-148
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• 2019

In this study, the removal of MB from saline solutions was evaluated by two methods by adsorption and electrodialysis; the adsorption of the mixture dye/salt on dried orange peel waste (OPW) was studied in batch method. In this study the biosorption of cationic dye by OPW was investigated as a function of initial solution pH, and initial salt (sodium chloride) concentration. The maximal dye uptake at $pH{\geq}3.6$ in the absence and in the presence of salt and the dye uptake diminished considerably in the presence of increasing concentrations of salt up to 8 g/L. The Redlich Peterson and Langmuir were the most suitable adsorption models for describing the biosorption equilibrium data of the dye both individually and in salt containing medium. As well, this work deals with the electrodialysis application to remove the dye. Synthetic solutions were used for the investigation of the main operational factors affecting the treatment performance; such as applied voltage, pH, initial dye concentration and ionic strength. The experimental results for adsorption and electrodialysis confirmed the importance of electrostatic interactions on the dye. The electrodialysis process with standard ion exchange membranes enabled efficient desalination of cationic dye solutions; there are two main factors in fouling: electrostatic interaction between cations of dyes and the fixed charged groups of the CEM, and affinity interactions.

• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.141-151
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• 1977

Distribution of tellurite and tellurate-reducing enzymes in the cell of Nocardia sp, the purifcation and the chemical properties of enzymes were investigated. Tellurite- and tellurate-reducing enzymes were located in the cytoplasm, but T. T. C. reduction part was in the cell membrane. Purification of tellurite- and tellurate-reducing enzymes was possible with the application of ammonium sulfate precipitation method and DEAE-Cellulose or CM-Cellulose column chromatographic method from the crude soluble part of the cell. On investigating the properties of purified enzyme, one of NADP, NADPH and reductive methylene blue(leucomethylene blue) was thought to react as a hydrogen donor. Both NADH and NADPH, or either of them would be physiological hydrogen donor.) In the reaction of this enzyme, either tellurite or tellurate reacts as a hydrogen acceptor, but on the other hand either selenate or selenate also reacts as a hydrogen acceptor.

• Applied Chemistry for Engineering
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• v.20 no.3
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• pp.329-334
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• 2009

Yttrium ions doped $TiO_2$ particles have been prepared using a low temperature combustion method. The physical properties were investigated, together with the activity of $TiO_2$ particles as a photocatalyst for the decomposition of methylene blue. From XRD results, the major phase of all the $TiO_2$ particles prepared under basic condition was an anatase structure but a rutile peak was observed when they are prepared under acidic condition. The crystallite size of $TiO_2$ particles was decreased as the molar ratio of CA/TTIP increased. The photocatalytic activity increased with an increase of CA/TTIP molar ratio and pH in the solution. In addition, the doping of 1.0 mole% yttrium ion on the $TiO_2$ enhanced the photocatalytic activity and showed the higher activity than commercial P-25 catalyst.

• Parasites, Hosts and Diseases
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• v.54 no.2
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• pp.191-195
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• 2016

The aim of this study was to evaluate different methods for Trichomonas vaginalis diagnosis during pregnancy in order to prevent maternal and perinatal complications. A total of 386 vaginal exudates from pregnant women were analyzed. T. vaginalis was investigated by 3 types of microscopic examinations direct wet mount with physiologic saline solution, prolonged May-Grunwald Giemsa (MGG) staining, and wet mount with sodium-acetate-formalin (SAF)/methylene blue method. PCR for 18S rRNA gene as well as culture in liquid medium were performed. The sensitivity and specificity of the microscopic examinations were evaluated considering the culture media positivity or the PCR techniques as gold standard. The frequency of T. vaginalis infection was 6.2% by culture and/or PCR, 5.2% by PCR, 4.7% by culture, 3.1% by SAF/methylene blue method and 2.8% by direct wet smear and prolonged MGG staining. The sensitivities were 83.3%, 75.0%, 50.0%, and 45.8% for PCR, culture, SAF/methylene blue method, and direct wet smear-prolonged MGG staining, respectively. The specificity was 100% for all the assessed methods. Microscopic examinations showed low sensitivity, mainly in asymptomatic pregnant patients. It is necessary to improve the detection of T. vaginalis using combined methods providing higher sensitivity, such as culture and PCR, mainly in asymptomatic pregnant patients, in order to prevent maternal and perinatal complications.

• Korean Journal of Materials Research
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• v.18 no.11
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• pp.583-591
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• 2008

In this study, two series of CNT/$TiO_2$ electrodes were prepared. The decrease of surface area compared with that of the pristine carbon nanotubes (CNTs) indicated the blocking of micropores on the surface of the CNTs; was further supported by scanning electron microscopy (SEM) and field emission SEM (FE-SEM) observations. The X-ray diffraction (XRD) results showed that the CNT/$TiO_2$ composites contained a mix of anatase and rutile forms of $TiO_2$ particles when the precursor was $TiO_2$ powder, whereas when the precursor was Ti ($OC_4H_7$) (TNB), the composites contained only the typical single and clear anatase $TiO_2$ particles. The energy dispersive X-ray spectroscopy (EDX) spectra showed the presence of C, O and Ti peaks for all samples. It was found that catalytic decomposition of methylene blue (MB) solution could be attributed to synthetic effects between the $TiO_2$ photocatalysis and electro-assisted CNTs network, and that photoelectrocatalytic oxidation increased with an increase of CNT composition. It was also found that the photoelectrocatalytic oxidation efficiency for MB is higher than that of photocatalytic oxidation. Moreover, the CNT/$TiO_2$ composites catalyst prepared by the impregnation method demonstrates higher photoelectrocatalytic activity than the mechanical mixture with the same CNT content.

• Korean Journal of Pharmacognosy
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• v.5 no.3
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• pp.147-154
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• 1974

Some crude drugs in ancient literatures have been used as traditional therapeutic agent of leucorrhea mainly caused by Trichomonas vaginalis and Candida albicans. Sixty six kinds of crude drugs in ancient literatures and ten constituents were selected as sample drugs. Trichomycin standard was tested to compare with the above drugs. To determine the anti-fungal effect of these drugs on Candida albicans Yu 1200, a test organism, screening test was conducted. Antifungal activities of crude drug water extracts were observed by means of two test methods : firstly through the agar slant method and secondly the counting chamber method which was used for acknowledged drug agents upon the result of the agar slant method. And in order to improve the fungicidal effect, the organisms were stained with 0.02% methylene blue solution. The results of the above test indicated that Fritillariae Rhizoma has antifungal action in the concentration of 310mcg/ml, Coptidis Rhizoma in 620mcg/ml, Meliae Cortex, Scutellariae Radix both in 5,000mcg/ml. Baicalin, catechol among the pure isolated constituents inhibited in the range of 50mcg/ml. This score was based on 50% inhibition in comparison with amounts of control organisms. Rhei Rhizoma, Mori Radicis Cortex, Linderae Radix, and Amomi globosi Fructus showed the antifungal effect moderately in 5,000mcg/ml, and baicalein and pectolinarin in 50mcg/ml in the limit of between 35% and 50% antifungal activity. Staining with 0.02% methylene blue showed that any of the crude drug extracts was unable to stain the cells, but trichomycin in 0.86unit/ml able to stain 12% of the cells. This result means that crude drugs probably do not have fungicidal but fungistatic action.

• Analytical Science and Technology
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• v.28 no.1
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• pp.40-46
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• 2015

Hydrochar has been generated from food waste via hydrothermal carbonization (HTC) reaction. As a solid product of HTC reaction, hydrochar has a great potential as an adsorbent of pollutants from the various media. The surface area and pore volumes are very important parameters to be served as an adsorbent. It requires an expensive equipment and consumes time to measure those parameter. Therefore, titration methods including iodine and methylene blue adsorption were evaluated to be correlated with that of BET analysis. Even though the absolute values of the computed surface area and pore volumes were not able to be matched directly, the patterns of change were successfully correlated. Among the reaction conditions, the reaction time and temperature at $230^{\circ}C$ for 4 h was determined as an optimization condition, which confirmed by titration method and BET analysis. Titration method for surface area and pore volumes computed by combination of iodine and methylene blue adsorbing values would be a simple and fast way of determining the optimization condition for hydrochar as an adsorbent produced by HTC reaction.

• Journal of Powder Materials
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• v.24 no.6
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• pp.477-482
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• 2017

Nitrogen-doped titanium dioxide (N-doped $TiO_2$) is attracting continuously increasing attention as a material for environmental photocatalysis. The N-atoms can occupy both interstitial and substitutional positions in the solid, with some evidence of a preference for interstitial sites. In this study, N-doped $TiO_2$ is prepared by the sol-gel method using $NH_4OH$ and $NH_4Cl$ as N ion doping agents, and the physical and photocatalytic properties with changes in the synthesis temperature and amount of agent are analyzed. The photocatalytic activities of the N-doped $TiO_2$ samples are evaluated based on the decomposition of methylene blue (MB) under visible-light irradiation. The addition of 5 wt% $NH_4Cl$ produces the best physical properties. As per the UV-vis analysis results, the N-doped $TiO_2$ exhibits a higher visible-light activity than the undoped $TiO_2$. The wavelength of the N-doped $TiO_2$ shifts to the visible-light region up to 412 nm. In addition, this sample shows MB removal of approximately 81%, with the whiteness increasing to +97 when the synthesis temperature is $600^{\circ}C$. The coloration and phase structure of the N-doped $TiO_2$ are characterized in detail using UV-vis, CIE Lab color parameter measurements, and powder X-ray diffraction (XRD).