Articoli di riviste: "Rutile – Research"

1

Karelin, V. A., A. N. Strashko, A. V. Dubrovin e A. V. Sazonov. "Research of Fluorination Process of Rutile Concentrate". Procedia Chemistry 11 (2014): 56–62. http://dx.doi.org/10.1016/j.proche.2014.11.011.

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Wu, Dao Xin, Zhou Lan Yin, Qi Yuan Chen, Jie Li e Ke Long Huang. "Research on Visible Light Photocatalytic Performance of Tungsten Doped TiO₂". Advanced Materials Research 236-238 (maggio 2011): 399–402. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.399.

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In this paper, W-doped rutile titania was prepared by low temperature hydrolysis using Tetrabutyl titanate. Powers were characterized by XRD、DRS、PL. At 1073K, Doped concentration have been in a certain range, Tungsten could be doped into the lattice of rutile TiO2in the way of replacement, which would cause no change in rutile TiO2crystalline state with sunlight as the light source, pH=2.0, catalyst concentration was 1.0g.L-1, concentration of methyl orange was 5.0mg.L-1. It has been shown that Tungsten doped TiO2powders(1.0%,1073K) has been the most photodegradation efficiency, and the degradation efficiency was 96.8% after 12h.

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Qi, Xue Mei, Xin Yuan Zhu, Jiang Wu, Yu Wu e Han Cheng Luo. "Sol-Gel Synthesis and Characterization of TiO₂-Based Photocatalyst and its Photoactivity Research". Advanced Materials Research 864-867 (dicembre 2013): 613–16. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.613.

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The TiO2-based photocatalysts have been synthesized by using sol-gel process and their photocatalytic activities were studied by the degradation of methylene blue (MB). It was shown that the calcination temperature has great influence on the crystalline phase transition of TiO2. For all the samples (Ag-doped and undoped TiO2photocatalysts) calcined at 573K, only anatase phase was observed from XRD diffraction spectra and the intensity of peaks is weak. After the calcined at 773K, a mixture of anatase-rutile phase appeared. The contents of rutile phase were about 85% and77% for undoped and Ag-adopted TiO2photocatalysts.There were only rutile phases for all the TiO2photocatalysts calcined at 973K observed from XRD diffraction spectra. Magnetically stirring time of A solution before added B had no obvious effects on the polymorphs transition of TiO2.

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Corfu, F., e A. J. Andrews. "A U–Pb age for mineralized Nipissing diabase, Gowganda, Ontario". Canadian Journal of Earth Sciences 23, n. 1 (1 gennaio 1986): 107–9. http://dx.doi.org/10.1139/e86-011.

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Concordant baddeleyite and rutile analyses from mineralized Nipissing diabase at Gowganda's Castle mine yield a U–Pb age of [Formula: see text]. Baddeleyite is a primary phase of the diabase; therefore the age dates the magmatic emplacement. The genesis of rutile is less certain: rutile could have formed during an episode of alteration, veining, and Ag mineralization, in which case the U–Pb age would also date the secondary event and demonstrate that Ag mineralization was related to the Nipissing magmatism. However, a primary magmatic origin of the rutile cannot be completely excluded for now; thus the U–Pb age may not constrain the time of Ag mineralization. Further research is needed to clarify this point.

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Kim, Na Yeon, Hyeon Kyeong Lee, Jong Tae Moon e Ji Bong Joo. "Synthesis of Spherical TiO2 Particles with Disordered Rutile Surface for Photocatalytic Hydrogen Production". Catalysts 9, n. 6 (28 maggio 2019): 491. http://dx.doi.org/10.3390/catal9060491.

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One of the most important issues in photocatalysis research has been the development of TiO2-based photocatalysts that work efficiently under visible light conditions. Here, we report the monodispersed, spherical TiO2 particles with disordered rutile surface for use as visible-light photocatalysts. The spherical TiO2 particles with disordered surface were synthesized by sol-gel synthesis, followed by sequential calcination, and chemical reduction process using Li/Ethylenediamine (Li/EDA) solution. Variation of the calcination temperature allowed the crystalline properties of the calcined TiO2 samples, such as the ratio of anatase and rutile, to be finely controlled. The content ratios of anatase phase to rutile phase leads to different degrees of disorder of the rutile surface, which is closely related to the photocatalysis activity. Chemical reduction using the Li/EDA solution enables selective reduction of the rutile surface of the calcined TiO2, resulting in enhanced light absorption. As a result, we were able to synthesize spherical TiO2 photocatalysts having a disordered rutile surface in a mixed crystalline phase, which is beneficial during photocatalysis in terms of light absorption and charge separation. When used as photocatalysts for hydrogen production under solar light conditions, the chemically-reduced TiO2 particles with both the disordered rutile surface and mixed crystalline phase showed significantly enhanced catalytic activity.

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Li, Li, Xiao Cui Guo e Yong Yan Zhou. "The Research of Chemical Resistance for Air Curing FEVE Fluorocarbon Coatings". Advanced Materials Research 239-242 (maggio 2011): 944–48. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.944.

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This study aims at analyzing the chemical resistance of a wide range additives in air curing ﬂuorocarbon coatings. Scanning Electron Microscope (SEM) and Immersion tests are used to detect coatings performances. The results showed that the surface state of coating does not affect the chemical resistance. While fumed SiO2 content in the coating is lower than 5.2%, chemical resistance are enhanced as the increasing of fumed SiO2 content, then maintained stability as content is more than 5.2%. Chemical resistance is increased gradually while the rutile TiO2 content of coating is less than 3.1%, and essentially unchanged while greater than 3.1%. As wax powder content increases, chemical resistance of coating decreased. Coupling agent content increases, leading to enhanced chemical resistance of the coating when coupling agent content is less than 5.8% and maintained stable while greater than 5.8%. So fumed SiO2, rutile TiO2, and coupling agent would inhance chemical resistance for coating to a certain extent, and wax powder would weaken the chemical resistance.

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7

Duan, Hai Ting, Qing Lin Hou e Yue Jin Liu. "Study of Uniform Design in the Optimizing Preparation Technology of the Rutile Titanium Dioxide Ternary Inorganic Coated". Applied Mechanics and Materials 329 (giugno 2013): 122–26. http://dx.doi.org/10.4028/www.scientific.net/amm.329.122.

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This paper researched the inorganic coated the rutile titanium dioxide process, a new inorganic coating (The rutile titanium dioxide ternary Inorganic coated were prepared by sol-gel method). The regression equation and the optimum conditions are founded by uniform design and the systemetical research of various factors on the properties of the rutile titanium dioxide ternary Inorganic Coated. Effect of The rutile titanium dioxide ternary Inorganic coated were characterized by nanoZS, Fourier infrared spectroscopic analysis (FT-IR) with NH3 as atom probe, scanning electron microscopy (SEM), transmission electron microscopy (TEM). The optimized formula of preparing the rutile titanium dioxide ternary inorganic coated is that the dispersant of 0.20%, the ZrO2 content of 0.6%, the SiO2 content of 3.0%, the Al2O3 content of 1.6%, the rotate speed of 340r/min when system temperature was 60°C-65°C, the seriflux concentration was 300g/L, the PH of the coated ZrO2 was 8.5-9.0, the PH of the coated SiO2 was 9.5-10.0, the PH of the coated Al2O3 was 6.0-6.5.

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8

Ackerson, Michael R., e Bjørn O. Mysen. "Experimental observations of TiO2 activity in rutile-undersaturated melts". American Mineralogist 105, n. 10 (1 ottobre 2020): 1547–55. http://dx.doi.org/10.2138/am-2020-7391.

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Abstract An estimate of TiO2 activity (aTiO2melt-sat) is necessary for the application of trace-element thermobarometry of magmatic systems where melts are typically undersaturated with respect to rutile/anatase. Experiments were performed in the system SiO2-Na2O-TiO2 to develop two independent methods of estimating aTiO2melt-sat—one based on the commonly applied rutile-saturation technique and another utilizing a novel Ti-in-tridymite thermometer. It is demonstrated that the rutile-saturation model can lead to an overestimate of aTiO2melt-sat relative to TiO2 activity calculated using the solubility of Ti in tridymite (SiO2) coexisting with rutile. Overestimation via the rutile-saturation technique is due to variations in the solubility mechanisms of Ti in the melt phase as a function of Ti content. In natural systems, overestimates of aTiO2melt-sat will lead to an underestimation of crystallization temperatures by Ti-based trace-element thermobarometers. Although this study is not directly applicable to natural systems, it lays the groundwork for future research on natural composition magmas to constrain TiO2 activity in melts.

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9

Li, Liang, e Lan Hua Zhou. "Technology Research on the Fluidization Treatment of High-Titanium Slag to Manufacture Synthetic Rutile". Applied Mechanics and Materials 397-400 (settembre 2013): 62–72. http://dx.doi.org/10.4028/www.scientific.net/amm.397-400.62.

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Oxidation and reduction of high-titanium slag were conducted in a self-designed fluidized bed. Detailed analyses of the leaching mechanism and kinetics were also performed. The effects of oxidation temperature, oxidation time, reduction temperature, and time on leaching products and on the leaching behavior of impurity were systematically investigated via conditional tests. The optimal conditions of the conditional tests are as follows: oxidation temperature of 1,0001,100°C, oxidation time of 3070 min, reduction temperature of 700800°C, and reduction time of 90150 min. Scanning electronic microscope and X-ray diffract analyses show that the phase structure of the high-titanium slag changed after fluidizing oxidation and reduction, which is when a major phase of the high-titanium slag was changed from pseudobrookite to rutile. The change had an important role on pulverization ratio reduction and on the creation of a new technology route for the use of titanium resource in Panzhihua in manufacturing synthetic rutile.

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Zhao, Pengsen, Guifa Li, Bingtian Li, Haizhong Zheng, Shiqiang Lu e Ping Peng. "Evolution Mechanism of Metallic Dioxide MO2 (M = Mn, Ti) from Nanorods to Bulk Crystal: First-Principles Research". Journal of Nanomaterials 2018 (2018): 1–14. http://dx.doi.org/10.1155/2018/9890785.

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Using first-principle calculations, the surface energy, cohesive energy, and electronic properties of α-MnO2 and rutile TiO2 nanorods and microfacets were investigated and clarified to, in the first instance, determine the evolution mechanism. The results show that the surface energies of α-MnO2 nanorods and microfacets conform to function 1.0401 Jm−2 + N × 0.608 Jm−2, while the surface energies of the rutile TiO2 nanorods and microfacets are governed by a 1.0102 × 1.1997 rule. Their electronic properties, such as the Mulliken population and Mulliken charge, can only be normalized by their surface areas to attain a linear function. Meanwhile, the surface energy of α-MnO2 with the nanostructure closely conforms to the function for normalized Mulliken population and Mulliken charge as f(x)=102.9×x+0.101 with an R2 value of 0.995. Thus, our research into the evolution mechanism affecting the surface effect of nanometer materials will be useful for investigating the intrinsic mechanism of the nanometer effect and doping process of metallic dioxide catalysts.

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11

Cao, Yu, Xiao Long Zhou, Jian Chun Cao, Yuan Yuan Peng, Jing Chao Chen e Jie Yu. "First Principles Study on Rutile SnO₂ Improving Gas Sensor Properties of Porous SnO₂-In₂O₃ Composites". Advanced Materials Research 476-478 (febbraio 2012): 828–34. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.828.

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we built the rutile SnO2 to study SnO2 improving gas sensor properties for rutile structure of SnO2 existing in the SnO2-In2O3 composite materials by X-ray analysis. The surface (110) of SnO2 is a stable structure by analysis of surface energy. Compared with oxidized surface (110), reduced surface (110) has better conductivity and stability. As a result, the CO adsorption changes the electric conductivity of the whole reductive (110) surface, and leads to the deviation of Fermi energy. Therefore, it is an important reason affecting gas sensor properties of the SnO2-In2O3 composite materials. By calculating and simulating the density functional first-principal, the research of the adsorption of rutile SnO2 towards CO provides a theoretical foundation for the argument of the gas sensitivity of porous SnO2-In2O3 composite materials towards CO with the increasing of SnO2 contents.

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Zhang, Han Ping, Xian Mei Chen, You You Tang e Qin Bo Cao. "Research on Removing Radioactivity Minerals Form Titanium Rough Concentration of Haibing". Advanced Materials Research 690-693 (maggio 2013): 1127–31. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.1127.

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Titanium rough concentrate in Haibing contains ilmenite, rutile and other valuable minerals, and also radioactive mineral monazite. Ore minerals contain 42.08% of TiO2 and 4.92% of ZrO2. Radionuclide specific activities results shown that intensity of radioactivity of 226Ra, Th and 40K are 2142.2Bq/kg, 8964.2Bq/kg and 724.72Bq/kg respectively. Through integration process of shaking table-weak magnetic-dry high intensity magnetic-electric separation, qualified titanium concentrate, azurite concentrate and monazite were obtained, which recovers the voluble minerals at maximal extent.

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13

Hsiao, Wen-Tien, Chun-Ming Kung, Jan-Show Chu, Keng-Liang Ou e Pei-Wen Peng. "Research of Electrosurgical Ablation with Antiadhesive Functionalization on Thermal and Histopathological Effects of Brain Tissues In Vivo". BioMed Research International 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/182657.

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Thermal injury and tissue sticking are two major concerns in the electrosurgery. In the present study, the effect of lateral thermal injury caused by different electrosurgical electrodes on wound healing was investigated. An electrosurgical unit equipped with untreated (SS) and titanium oxide layer-coated (TiO2-coated) stainless steel needle-type electrodes was used to create lesions on the rat brain tissue. TiO2layers were produced by radiofrequency plasma and magnetron sputtering in the form of amorphous (TO-SS-1), anatase (TO-SS-2), and rutile (TO-SS-3) phase. Animals were sacrificed for evaluations at 0, 2, 7, and 28 days postoperatively. TO-SS-3 electrodes generated lower levels of sticking tissue, and the thermographs showed that the recorded highest temperature in brain tissue from the TO-SS-3 electrode was significantly lower than in the SS electrode. The total injury area of brain tissue caused by TO-SS-1 and TO-SS-3 electrodes was significantly lower than that caused by SS electrodes at each time point. The results of the present study reveal that the plating of electrodes with a TiO2film with rutile phases is an efficient method for improving the performance of electrosurgical units and should benefit wound healing.

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Stashans, Arvids, e Jairo Escobar. "Effects of vanadium impurity on TiO2 properties". International Journal of Modern Physics B 29, n. 15 (25 maggio 2015): 1550094. http://dx.doi.org/10.1142/s0217979215500940.

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Our present work is based on the density functional theory (DFT) studies of TiO 2 crystals doped with V impurities. Both rutile and anatase structures have been considered within the present research and different defect concentrations have been used as well. Our calculations reveal equilibrium geometry of the system showing atomic rearrangement around the point defect being mainly inward with respect to the impurity. Magnetism and electronic structure based on the density of states (DOS) patterns for both rutile and anatase crystals have been obtained and discussed in detail. It is shown that local magnetic moments arise mainly from the 3d states of the impurity atom with some admixture of 2p states from the vanadium-nearest O atoms.

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Uekawa, Naofumi, Miki Suzuki, Takahiro Ohmiya, Fumihiko Mori, Yong Jun Wu e Kazuyuki Kakegawa. "Synthesis of rutile and anatase TiO2 nanoparticles from Ti-peroxy compound aqueous solution with polyols". Journal of Materials Research 18, n. 4 (aprile 2003): 797–803. http://dx.doi.org/10.1557/jmr.2003.0110.

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Ti-peroxy compound was synthesized from Ti(O-iPr)4 and H2O2. Anatase and rutile TiO2 nanoparticles were prepared by heating the Ti-peroxy compound diluted with a polyol aqueous solution at 368 K for 24 h. In this research, ethylene glycol, glycerin, erythritol, and D-mannitol were used as polyols in the diluting solution. The ratio of anatase/rutile of the TiO2 obtained depended on the polyol concentration in the diluting solution. Furthermore, the polyol concentration at which single-phase anatase could be obtained was lowest when the number of OH groups in the polyol molecule was the highest. With increasing polyol concentration, the obtained TiO2 nanoparticles showed increasing specific surface area and decreasing particle size.

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Mihailescu, Dănuţ, Octavian Frincu e Marius Corneliu Gheonea. "The Comparative Analysis of the Concentration of Microparticles during Mechanized MAG Welding Using Cored Wires". Advanced Materials Research 814 (settembre 2013): 76–81. http://dx.doi.org/10.4028/www.scientific.net/amr.814.76.

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Use of cored wire - shielding gas (gas mixture) pair, during mechanized MAG welding, causes the microparticles formation which is harmful for the welder’s health. The paper presents the experimental method for determining the concentration of the microparticles generated during MAG welding when rutile cored wires (standard and low fume emission) and metal powder cored wires (standard and low fume emission) are used. Carbon dioxide and the shielding gas mixture are investigated, too. Four types of cored wires were comparatively analysed, when three wire speed values were applied. The research of the microparticles concentration was conducted after each welding bead deposition, at the upper part of the welding enclosure, using MicroDust Pro particulate monitor. After each weld bead was deposited, the metal frame of the welding enclosure was removed, and, the fumes and gases, produced during the welding process, were eliminated through two fans, positioned inside and outside of the equipment. Using rutile cored wire with low fume emission, a decrease of microparticles concentration up to 30% is noticed in comparison with standard rutile cored wire. Using metal powders cored wire with low fume emission, the microparticles concentration is diminished with 12.5% comparing with standard metal powders cored wire.

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Bracciali, Laura. "Coupled Zircon-Rutile U-Pb Chronology: LA ICP-MS Dating, Geological Significance and Applications to Sediment Provenance in the Eastern Himalayan-Indo-Burman Region". Geosciences 9, n. 11 (5 novembre 2019): 467. http://dx.doi.org/10.3390/geosciences9110467.

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U-Pb dating by LA ICP-MS is one of the most popular and successful isotopic techniques available to the Earth Sciences to constrain timing and rates of geological processes thanks to its high spatial resolution, good precision (absolute U/Pb age resolution of ca. 2%, 2s), rapidity and relative affordability. The significant and continuous improvement of instrumentation and approaches has opened new fields of applications by extending the range of minerals that can be dated by this method. Following the development and distribution to the community of good quality reference materials in the last decade, rutile U-Pb thermochronology (with a precision only slightly worse than zircon) has become a commonly used method to track cooling of deep-seated rocks. Its sensitivity to mid- to low-crustal temperatures (~450 °C to 650 °C) is ideal to constrain exhumation in active and ancient orogens as well as thermal evolution of slow-cooled terranes. Recrystallization and secondary growth during metamorphism and the presence of grain boundary fluids can also affect the U-Pb isotopic system in rutile. A growing body of research focusing on U-Pb dating of rutile by LA ICP-MS is greatly improving our understanding of the behavior of this mineral with regards to retention of radiogenic Pb. This is key to fully exploit its potential as a tracker of geological processes. The latest developments in this field are reviewed in this contribution. The combined application of U-Pb zircon and rutile chronology in provenance studies, particularly when complemented by lower-T thermochronometry data, allows the isotopic characterization of the sources across a wide range of temperatures. The benefits of applying detrital zircon-rutile U-Pb chronology as a coupled provenance proxy are presented here, with a focus on the Eastern Himalayan-Indo-Burman region, where a growing number of successful studies employs such an approach to help constrain river drainage and basin evolution and to infer feedback relationships between erosion, tectonics and climate.

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Gusev, A. A., e E. G. Avvakumov. "Conducting materials based on nanodispersed titanium monoxide". Science of Sintering 39, n. 3 (2007): 295–99. http://dx.doi.org/10.2298/sos0703295g.

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The possibility of obtaining the TiO compound during mechanical activation of rutile and titanium in a planetary mill was studied depending on ball size and the activation time. The initial substances, TiO2 (rutile) and Ti (metal), were shown to change into TiO almost completely during grinding as early as after ten minutes. In this case the cubic modification of TiO formed, with the lattice parameter a=4.185(7) ? and particles of 1-3 ?m, which consisted of units about 10 nm in size. The other subject of our research was the dependence of the conductivity of the products on the conditions under which they were moulded and sintered under argon. The conductivity of the samples was in the range 300 to 600 S cm-1. Their chemical resistance equaled that of Ti4O7 samples.

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Li, Shi Jie, Jie Hu e Xiao Ming Cao. "Research on Growth Process and Microstructure of Microarc Oxidation Coating on Titanium". Advanced Materials Research 383-390 (novembre 2011): 1905–9. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.1905.

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Porous ceramic layer was deposited on pure titanium substrate by micro-arc oxidation(MAO). XRD and SEM were employed to characterize the phase composition and microstructure of the film. The effects of micro-arc oxidation time on microstructure and phase composition of TiO2 coating were analysed. The results show that, with the increase of oxidation time, the number of micro-pores decreases, while the size of micro-pores, roughness and thickness of MAO coating increase.MAO coating shows dentrites grew, but not traditionally nucleation and grow. Oxidation coating growth inward, while at the same time to growth outward. Grow into a dense ceramic membrane layer inward, outward growth into the porous layer. The coating is mainly composed of Ti, anatase and the rutile phases.

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Li, Mei Jun, e Wen Bin Cao. "Research on Solvothermal Synthesis of Phase Composition Controllable Nanocrystalline TiO₂ Powders". Advanced Materials Research 284-286 (luglio 2011): 820–24. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.820.

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N-doped TiO2 powders have been prepared by solvothermal synthesis using TiCl3 aqueous solution as precursor. The as-synthesized powders are composed of anatase and rutile and show light-yellow in color. The grain size is ranged from 10.3 nm to 19.1 nm by Scherrer's method and the specific surface area is ranged from 21 m2/g to 122 m2/g. X-ray photoelectron spectroscopy (XPS) results indicate that N atoms have been doped into the lattice of TiO2. Ti-N bonding and radical groups such as ×OH were detected on the surface of the powders. The synthesized N-doped TiO2 powders shows excellent visible-light photocatalytic activities and their absorption edge have been red-shifted to 560 nm.

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Shtyka, Oleksandr, Viktar Shatsila, Radoslaw Ciesielski, Adam Kedziora, Waldemar Maniukiewicz, Sergey Dubkov, Dmitry Gromov et al. "Adsorption and Photocatalytic Reduction of Carbon Dioxide on TiO2". Catalysts 11, n. 1 (31 dicembre 2020): 47. http://dx.doi.org/10.3390/catal11010047.

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The photocatalytic activity of TiO2 depends on numerous factors, such as the chemical potential of electrons, charge transport properties, band-gap energy, and concentration of surface-active sites. A lot of research has been dedicated to determining the properties that have the most significant influence on the photocatalytic activity of semiconductors. Here, we demonstrated that the activity of TiO2 in the gas-phase reduction of CO2 is governed mainly by the desorption rate of the reaction intermediates and final products. This indicates that the specific surface area of TiO2 and binding strength of reaction intermediates and products are the main factors affecting the photocatalytic activity of TiO2 in the investigated process. Additionally, it was shown that rutile exhibits higher photocatalytic activity than anatase/rutile mixtures mainly due to its high efficiency in the visible portion of the electromagnetic spectrum.

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Yang, Zhi Yuan, Shi Cun Qu e Xiao Na Lu. "Research on Preparation of Nanocrystalline Titanium Oxide Film and its Super-Hydrophilic Property". Advanced Materials Research 744 (agosto 2013): 396–99. http://dx.doi.org/10.4028/www.scientific.net/amr.744.396.

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Sol-Gel Coating was used to prepare nanocrystalline titanium oxide film, with which some metal ions were mixed up. In the end, XRD and SEM were used to analyze the composition and the property of the morphology, and then ultraviolet light was used to test the super-hydrophilic property. The results show that the photocatalytic property of the metal ion-doped films is stronger than that of the non-doped TiO2 films, but weaker than the metal ion-doped SiO2/TiO2 films. For the doping 0.05% TiO2 films, the Ce-doped titanium dioxide on the degradation of methyl orange is the slowest. After calcined at 500°C for 2 hours, rutile and anatase crystals are mixtured; Grain size of the films is in 42.5-85.7 nm.

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Asamoah, Richmond K. "Specific Refractory Gold Flotation and Bio-Oxidation Products: Research Overview". Minerals 11, n. 1 (19 gennaio 2021): 93. http://dx.doi.org/10.3390/min11010093.

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This paper presents a research overview, reconciling key and useful case study findings, towards uncovering major causes of gold refractoriness and maximising extraction performance of specific gold flotation and bio-oxidation products. Through systematic investigation of the ore mineralogical and gold deportment properties, leaching mechanisms, and kinetic behaviour and pulp rheology, it was observed that the predominant cause of the poor extraction efficacy of one bio-oxidised product is the presence of recalcitrant sulphate minerals (e.g., jarosite and gypsum) produced during the oxidation process. This was followed by carbonaceous matter and other gangue minerals such as muscovite, quartz, and rutile. The underpining leaching mechanism and kinetics coupled with the pulp rheology were influenced by the feed mineralogy/chemistry, time, agitation/shear rate, interfacial chemistry, pH modifier type, and mechano-chemical activation. For instance, surface exposure of otherwise unavailable gold particles by mechano-chemical activation enhanced the gold leaching rate and yield. This work reflect the remarkable impact of subtle deposit feature changes on extraction performance.

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Liu, Fang, Zhi Bin Zhang, Ling Ling Xu e Ming Shu Tang. "Study on the Resistance of Ultraviolet Radiation of Composite Materials Based on Epoxy Resin". Advanced Materials Research 391-392 (dicembre 2011): 812–16. http://dx.doi.org/10.4028/www.scientific.net/amr.391-392.812.

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Previous research indicated epoxy resin based repairing materials have been widely used due to its outstanding advantages in strength, durability corrosion, abrasion resistance and reasonable price, etc. But its nonperforming resistance of ultraviolet radiation restricted popularization and using. In this paper the effect of inorganic fillers (quartz sand, rutile type titanium dioxide and talc powder) and organic fillers (HALS-770 and UV-P) on the Compressive strength of RME irradiated was studied. The results indicated that inorganic and organic fillers revealed good shielding effect. The inorganic fillers decreased the compressive strength of RME about 20MPa, and talc powder was better than quartz sand and rutile type titanium dioxide. Organic fillers had unaffected in strength, and combined use of HALS-770 and UV-P had better resistance than alone. The strength retention of RME with talc powder and combined with HALS-770 and UV-P irradiated 4500h were 85.65% and 93.5%.

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Gleń, Marta, e Barbara Grzmil. "Photostability and optical properties of modified titanium dioxide". Pure and Applied Chemistry 84, n. 12 (12 ottobre 2012): 2531–47. http://dx.doi.org/10.1351/pac-con-12-01-09.

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Abstract (sommario):

The influence of different modifiers, P2O5, K2O, Al2O3, SiO2, CeO2, and ZrO2, on the optical properties and photostability of rutile titanium dioxide was studied. The research was aimed at obtaining pigmentary rutile titanium dioxide with the enhanced photostability. The optical properties such as brightness, white tone, and gray tone were improved when titanium dioxide samples were modified with zirconium instead of cerium. Titanium dioxide products modified additionally with Al2O3 displayed improved optical properties by comparison with appropriate titanium dioxide products lacking introduced aluminum. In comparison with unmodified material (∆E* = 21.8), a considerable increase of the photostability of modified titanium dioxide was observed. The lowest photoactivity, in the range of ∆E* = 0.96–2.45, was measured for the TiO2-PKAlSiCe series. A selective leaching method and X-ray diffraction (XRD) analysis were used to determine the distribution of modifiers in titanium dioxide materials. It was concluded that the differences in both photoactivity and optical properties of modified titanium dioxide depend on its phase composition.

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Graham, Simon J., Lyndsey L. Benson e Martin Jackson. "Synthetic rutile derived titanium alloy development utilising the Metalysis Process and field assisted sintering technology". MATEC Web of Conferences 321 (2020): 07001. http://dx.doi.org/10.1051/matecconf/202032107001.

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Abstract (sommario):

Utilising novel extraction and processing technologies allows for the realisation of an alternative titanium alloy production route, with many benefits over the traditional Kroll-based one. The route proposed has the potential to reduce the cost of titanium and offers the ability to create alloys which are difficult to make conventionally. It combines the Metalysis Process, an electrolytic metal extraction technique, with field assisted sintering technology (FAST), a rapid and effective solid-state sintering technique. The Metalysis Process reduces metal oxide powders directly into metal powders, which can then be consolidated using FAST. Using synthetic rutile (SR) as the feedstock, compared to pigment grade rutile and TiCl4, further reduces the cost of titanium produced via this route. This research investigates the use of this route to create a range of pseudo-binary Ti-Fe alloys, by co-reducing SR with iron (III) oxide (Fe O ). Various techniques were used to analyse the feedstock, reduced alloy powders and consolidated material post-FAST to 23 determine chemistry and microstructure.

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Jiao, Bao Xiang, Meng Ting Li, Xia Zhang e Xu Wang. "Preparation and Research on Luminescent Properties of Eu-Doped TiO₂-ZnO Composite Powders". Advanced Materials Research 652-654 (gennaio 2013): 622–27. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.622.

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Abstract (sommario):

The Eu-doped TiO2nanocrystals with different content of Eu3+and the Eu-doped TiO2-ZnO composite powders with different content of ZnO were prepared by sol-gel method. The X-ray diffraction (XRD) spectra and photoluminescence(PL) spectra indicated that all of the Eu-doped TiO2have anatase structure. It indicated that the incorporation of Eu3+can inhibit the transformation of TiO2from anatase to rutile phase. With the increase of the content of Eu3+, the luminous intensity first increased and then decreased, and luminescent properties were best when the content of Eu3+is 1.1%. Considering the Eu-doped TiO2-ZnO composite powders, with the increasing of the proportion of ZnO, a Zn2TiO4phase has been gradually generated. When the content of ZnO up to 40%, the luminescent properties are the best.

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28

Lei, Su, e Huang Yi. "Research on Magnetic Property of Environmental Friendly Material SnO2: Mn, S". E3S Web of Conferences 237 (2021): 01023. http://dx.doi.org/10.1051/e3sconf/202123701023.

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Abstract (sommario):

Tin dioxide (SnO2) is a commonly known material with the rutile structure of wide band gap ntype semiconductor which is widely used like ZnO common oxide materials in daily life. But comparing with ZnO, it has a wider band gap (about 3.6 eV), and a higher exciton binding energy 130 meV. Because of its excellent optical, electrical and other excellent physical and chemical characteristics, SnO2 has been widely adapted in thermoelectric film, gas sensor, photovoltaic devices, magnetic materials, and other related fields. A large number of theories and experiments illustrate that, after the proper doping, the remarkable improvements can be achieved. Based on the first principle, we investigated the photoelectric properties and magnetic properties when the Mn and S were doped in SnO2. It was shown by calculation that a Mn atom provides 1.52 μB magnetic moment and a S atom provides 0.06 μB, while O and Sn atoms rarely contribute to the system. In the system the magnetism is mainly derived from the Mn-3d electronic spin polarization.

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Wei, Jiang, Jian-Xiong Liu, Zheng-Yu Wu, Zhao-Lin Zhan, Jin Shi e Kun Xu. "Research on the Electrochemical Performance of Rutile and Anatase Composite TiO2 Nanotube Arrays in Lithium-Ion Batteries". Journal of Nanoscience and Nanotechnology 15, n. 7 (1 luglio 2015): 5013–19. http://dx.doi.org/10.1166/jnn.2015.9847.

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30

Gleń, Marta A., e Barbara U. Grzmil. "The Influence of Modifiers on the Pigmentary Properties of Titanium Dioxide". MRS Proceedings 1485 (2012): 59–64. http://dx.doi.org/10.1557/opl.2013.214.

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Abstract (sommario):

ABSTRACTIn the present work modified titanium dioxide products are prepared. The influence of introduced modifiers (phosphorus, potassium, aluminium, and tin) on the photoactivity, optical properties, and phase composition of titanium dioxide is studied. The molar contents of P2O5, K2O, Al2O3, and SnO2 in relation to TiO2 are 0.10, 0.18, 0.24, and 0.08-1.32 mol%, respectively. The research is aimed at obtaining the pigmentary rutile TiO2 with the highest possible photostability and improved optical properties.

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Yanagida, K., W. Kurniawan, C. Salim e H. Hinode. "Decomposition of Nitrous Oxide over Cu/TiO2 Catalysts: The Effect of Cu Loading, TiO2 Structure, and Reaction Conditions". Indonesian Journal of Computing, Engineering and Design (IJoCED) 1, n. 2 (30 settembre 2019): 99. http://dx.doi.org/10.35806/ijoced.v1i2.63.

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Abstract (sommario):

Decomposition of nitrous oxide (N2O) over titania (TiO2) supported copper (Cu) catalyst was investigated with the existence of oxygen and water vapor. The catalytic activity of TiO2 was promoted by copper loading. It was found that there are optimum levels of copper loading on TiO2, and these values are correlated to the specific surface area of TiO2 support being used. The relationship between the catalytic activity for decomposition of N2O and the crystal structure of TiO2 was also investigated. The result revealed that Cu/TiO2 catalysts with the rutile structure has a higher activity toward N2O decomposition than those with the anatase structure. In this research, Cu(5wt%)/TiO2 prepared from TiO2 JRC-TIO-4 (reference catalyst provided by Catalysis Society of Japan) which was mainly constituted of rutile showed the highest activity for N2O decomposition and it could decompose N2O completely at 650℃. The catalytic activity was inhibited by the existence of oxygen. However, there was no influence of water vapor to the catalytic activity of Cu/TiO2 for N2O decomposition.

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32

Li, Xing Long, Yong Hua Zang, Zhen Juan Wu e Ying Xu. "Application of TiO₂ to Improve the Brightness Stability of HYP Containing Coated Paper". Advanced Materials Research 236-238 (maggio 2011): 1367–71. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1367.

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Abstract (sommario):

Eco-friendly high-yield pulps (HYP) are becoming increasingly used to product high value-added fine paper that is traditionally produced exclusively with chemical pulps. However, due to the presence of a large quantity of photosensitive lignin in the HYP pulp to more effectively utilize woods resources, there is a concern on the long term brightness stability of HYP containing paper. In this research, various TiO2was added to coating colors to improve the light fastness properties of HYP containing coated paper. The effect on the stability of optical properties of coated paper including brightness, opacity, color difference and the degree of brightness reversion before and after accelerated aging were studied. It was shown that the brightness stability of the HYP containing coated paper increased with increased addition of TiO2. Rutile TiO2was especially more effective than other types of TiO2on yellowing inhibition of coated paper. At a dosage of 3 parts of rutile TiO2, the brightness stability of coated paper containing 20% of HYP was found to be even better than paper made of 100% chemical pulp coated with conventional coating color.

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Duong, Binh Ngoc, Than Ngoc Truong e Thao Thi Nguyen. "The Upgrading of Ha Tinh Ilmenite to Synthetic Rutile by Becher Process". Materials Science Forum 985 (aprile 2020): 115–23. http://dx.doi.org/10.4028/www.scientific.net/msf.985.115.

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Abstract (sommario):

Becher process was applied for upgrading Ha Tinh ilmenite concentrate (54-55% TiO2) to synthetic rutile. The process includes reduction of ilmenite concentrate using anthracite coal as reductant, followed by aeration of reduced ilmenite in ammonium chloride solution (NH4Cl). The controlled parameters were temperature and NH4Cl concentration. The results showed that the degree of iron metallization was 83% after 4 hours of reduction at 1150 °C. Most of the metallic iron (98%) was successfully rust after 9 hours of aeration at 70°C, 7/1 of liquid/solid ratio (L/R), 4 liter/minutes (L/min) of air flow rate and 0.5% of NH4Cl concentration. The addition of acetic acid or citric acid in to the aeration solution has facilitated the aeration process. The aeration time could be vastly reduced when ammonium chloride solution used in aeration was replaced by the mixture of CH3COOH 0.075M and CH3COONa. Leaching with H2SO4 15% has improved TiO2 content from 82% in the aerated ilmenite to approximately 89% in synthetic rutile. The research work has proved that Becher process is applicable for the beneficiation of Ha Tinh ilmenite concentrate.

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34

Zhou, Mingliang, Xuhong Chen, Lingjiang Zhang e Wen Zeng. "High Performance Novel Gas Sensor Device for Site Environmental Protection Using Ti0.5Sn0.5O2 Nanomaterials". Journal of Nanoelectronics and Optoelectronics 15, n. 12 (1 dicembre 2020): 1423–28. http://dx.doi.org/10.1166/jno.2020.2888.

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Abstract (sommario):

SnO2 and TiO2 have attracted the most attention due to their unique chemical and electrical properties in basic research of functional materials and applied research of materials. The performance of composite oxide or solid solution material is better than that of monomer oxide. Therefore, SnO2?TiO2 composite oxide system has become one of the active composite materials studied at home and Abroad. A large number of reports have shown that a certain proportion of SnO2?TiO2 composite material can obtain the best gas-sensitive performance, but this proportion has a great relationship with the crystal structure and process conditions of the material preparation. Therefore, in this paper, Ti0.5Sn0.5O2 solid solution materials with Sn/Ti molar ratio of 1/1 were prepared at different sintering temperatures, and their structure and gas-sensitive properties were studied. After sintering at 650 °C, the samples were mainly closely combined with rutile SnO2 and anatase type TiO2 particles, and some Sn and Ti ions were replaced. After sintering at 1050 °C, the composite mode of SnO2/TiO2 was dominated by solid solution and rutile Ti?Sn?O2 solid solution. The samples prepared at different sintering temperatures have different gas-sensitive properties for methanol, ethanol and other organic gases and the gas-sensitive properties of the prepared SnO2?TiO2 composite decreased with the increase of sintering temperature.

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35

Badida, L. V., A. V. Maslov e G. A. Mizens. "Provenance reconstructions. Article 3. Modern research methods for heavy detrital minerals (garnet, tourmaline, chromespinelide, rutile, chloritoid, pyroxene and amphibole)". LITHOSPHERE (Russia) 20, n. 2 (25 aprile 2020): 149–67. http://dx.doi.org/10.24930/1681-9004-2020-20-2-149-167.

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Abstract (sommario):

Research subject. This article considers accessory minerals, which, unlike zircons, are present in the vast majority of common clastic rocks. Materials and methods. The data on the chemical composition of minerals (garnet, tourmaline, chromespinelide, rutile, chloritoid and clinopyroxene) extracted from the Riphean and Vendian, as well as Upper Permian and Lower Triassic sandstones of the Southern Urals, were used to illustrate the features of applying various methods and techniques. In addition, numerous examples from publications are presented. Results. A number of modern methods for studying accessory minerals, which might be used to elucidate the composition and characteristics of the provenance rocks for terrigenous strata, were reviewed. Conclusions. It is shown that, similar to zircons, accessory minerals possess a significant potential in terms of providing important data on parent rocks.

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36

Gheonea, Marius Corneliu, Danut Mihailescu e Elena Scutelnicu. "Influence of Shielding Gas and Wire Type on the Microparticles Size Generated during MAG Welding Process". Applied Mechanics and Materials 809-810 (novembre 2015): 461–66. http://dx.doi.org/10.4028/www.scientific.net/amm.809-810.461.

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Abstract (sommario):

Exposure of welders to welding fumes and microparticles produced during electric welding can be dangerous and may cause serious maladies. It is important to understand the formation mechanism of microparticles generated during welding process on the one hand and the methods to diminish the risk on the welder’s health on the other hand. Experimental research results related to the assessment of microparticles size, generated during MAG welding process, are presented and discussed in detail in this paper. Rutile flux-cored and low fume metal powder cored wires with 1.2 mm diameter in combination with CO2 shielding gas or M21 gas mixture (Corgon 18) have been used in the investigations. The experimental tests were performed in a special enclosure, equipped with Glass Fiber Filters and a Philips vacuum, with the aim to capture the microparticles developed by the MAG welding process. The microparticles collected during the experimental program have been analysed and measured by electron microscopy method with (SEM/ESEM - EDAX) Quanta 200 microscope. The study showed that low fume metal powder cored wires determined the achievement of smaller microparticles in comparison with rutile flux-cored wires. Finally, several conclusions emerged from the findings of this study are synthetically presented.

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Yuniarti, Elvan. "Studi Komputasi Sifat Elektronik dan Sifat Optik Fotoelektroda Titanium Dioksida (TiO2) pada Fasa Anatase dan Rutile". Al-Fiziya: Journal of Materials Science, Geophysics, Instrumentation and Theoretical Physics 2, n. 1 (22 giugno 2019): 40–48. http://dx.doi.org/10.15408/fiziya.v2i1.11116.

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Abstract (sommario):

This research focuses on photoelectric Titanium Dioxide (TiO2) as a tool for Sensitive Solar Cell Dyes (DSSC). Anatase and rutile phase. some of the things studied were: crystal structure, band structure, structural structure, photoelectric optical properties of TiO2. The method used in this study is a calculation using the DFT theory and quantum expresso software. The TiO2 cell unit has the optimal shape for the pure antase TiO2 model which has a parameter a = b 3.785 units, c = 9.514 units, α = β = γ = 90O. The average T-O bond length is 1,966 barrels. This phase has a triclinic lattice type with group space P1 (1) which has a volume unit of 136.2991 A3. The Rutile phase has a parameter a = b = 4.5593 with c = 2,958 stars with α = β = γ = 90O. The average T-O bond length is 2.77 barrels. This phase has a Triclinic lattice type with a space group P1 (1) with a volume unit of 52.44233 A3. The anatase phase of TiO2 has indirect characteristics, namely M and Г. coordinate. Based on the calculation of the large bandgap obtained at 3.2 eV. This is in accordance with the data experiment. The energy of the band tape must be greater than the minimum energy needed for the redox reaction in the dye. While the characteristics of the ribbon emphasize the value of the absorption coefficient in light and the rate of electron recombination. Materials with direct band gab have high combination coefficients but with high combination levels. This greatly influences the DSSC efficiency value. TIO2 Rutile phase has a direct property of 3.5 eV for potential Hubbard energy U + 7. This value is closed to the experiment result.

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Komalasari, Maya, e Bambang Sunendar. "Synthesis and Characterization of TiO₂ Nanoparticle Using Starch as a Template by Sol-Gel Method for the Application of UV Protection". Advanced Materials Research 789 (settembre 2013): 237–41. http://dx.doi.org/10.4028/www.scientific.net/amr.789.237.

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Abstract (sommario):

Nanotechnology is one of the key technology had been developed since in all fields including textile industries for medical, hygienic, and technical textiles. Particle size with nanohad been indicated in particular for the application of controlled release material for functional textiles. TiO2nanopowder has remarkable photo-catalytic and semiconductor as material for various advanced technology fields of application such as UV Protection. In this research the synthesis of TiO2nanoparticle and characterization had been conducted successfully by sol-gel method. The starch was used as a template to get nanoparticles structure. TiO2sol with narrow particle size distribution using TiCl4as the starting material. The sol was prepared by a process where HCl was added to a gel of hydrated titanium oxide to dissolve it. The effect of preparation parameters were investigated, by deionized water : HCl 1 M was slowly added to TiCl4at 5 °C. In this study the production of anatase or rutile TiO2nanostructured powder by forced hydrolysis of aqueous Ti (IV) chloride solution and concentration from 0,3, 0,5 then 1 M. TiO2sphere were fabricated by a facile and low cost stable starch assisted by sol-gel method. Aqueous solution of starch was added and then heated in temperature 80°C and aqueous solution of ammonium hydroxide was added to adjust pH to 8. After aging period of time, the white precipitate was filtered and then calcined in temperature 5000C. The as-obtained samples were characterize,kjnhjd by SEM (Scanning Electron Microscope), UV-vis diffuse reflectance spectroscopy, X-Ray Diffraction (XRD) and Brunauer Emmett Teller (BET) analysis. The particle size is less than 100 nm and if it uses template particle TiO2more uniform distribution and spherical shape with particle size 170 200 nm. Crystalinity particle is 4 19 nm and the phase structure of anatase and rutile. The energy band gap semiconductor TiO2synthesis is 3.1 to 3.7 eV. Surface area without template starch 40.655 m2/g, with total for volume 0.278 cm3/g and pore size of 27 nm, and used template starch surface area 35.488m2/g with total for volume 0.196 cm3/g and pore size of 22 nm. Based on this research, the best a crystal phase for UV protection application is rutile phase.

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Dubenko, Anastasiia V., Mykola V. Nikolenko, Eugene V. Aksenenko, Andrii Kostyniuk e Blaž Likozar. "Mechanism, Thermodynamics and Kinetics of Rutile Leaching Process by Sulfuric Acid Reactions". Processes 8, n. 6 (27 maggio 2020): 640. http://dx.doi.org/10.3390/pr8060640.

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Abstract (sommario):

Rutile decomposition by sulfuric acid, including the formation of two salts, Ti(SO4)2/TiOSO4, is thermodynamically modelled. It is shown that TiO2 can spontaneously dissolve in H2SO4 solutions. However, titania is considered as an inert (ballast) phase component of titanium-containing raw materials due to the decelerated separate nature of such chemical transformations. It is concluded that the hampered related kinetics of dissolution can be attributed to the lability of Ti(IV) cations/the specific engineered features of the hierarchical crystalline structure. It is suggested that the breaking of Ti–O–Ti bonds without additional mechanical strains in crystal lattice geometry becomes more advantageous when smaller negative anions/fluoride ions can be used. The analysis of sulfate-fluoride extraction leaching of titanium confirmed that a decrease in the Gibbs energy in the presence of F occurs. It is indicated by kinetic research studies that the addition of corrosive sodium reagent (NaF) reduces the activation by 45 kJ/mol, which results in intensification. A mechanism is proposed for the interactions involving the Ti–O–Ti cleavage on the surface/the H2SO4-induced Ti dioxide degradation on the sites of defects. Moreover, F acts as a homogeneous/heterogeneous bifunctional catalyst.

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Hampel, Boglárka, Lucian Baia, Klara Hernadi e Zsolt Pap. "The Influence of the Ratio of Au and Pt Nanoparticles in Ternary Composites with TiO2". Metals 11, n. 4 (13 aprile 2021): 628. http://dx.doi.org/10.3390/met11040628.

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Abstract (sommario):

In the present work, ternary composites were synthesized from commercial titanias (Evonik Aeroxide P25, Aldrich anatase—AA and Aldrich rutile—AR) and two noble metals (gold and platinum). This research focuses on the composition of the photocatalysts, especially on the noble metals. The ratio between the noble metals varies from 0.25 to 0.75% in each composite for each noble metal. Transmission electron microscopy (TEM), X-ray diffraction (XRD) and diffuse reflectance spectroscopy (DRS) measurements were carried out to investigate the structural and optical properties. From the TEM, it can be observed that the particle sizes of the noble metals were between 1 and 4 nm, while the (anatase and rutile) crystals of P25 were 20–40 nm. The XRD showed that the semiconductors’ composition remained unchanged during/after the deposition of noble metal nanoparticles. By the DRS measurements, using the Kubelka–Munk equation, it can be concluded that the deposition of the noble metal nanoparticles resulted the decrease of the bandgap energies of the titanias. The photocatalytic activity was investigated under the irradiation of UV light. Oxalic acid and salicylic acid were used as model pollutants. The hydrogen production capacity was investigated as well, where the sacrificial agent was oxalic acid, and UV irradiation was used.

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Jiang, Man, Ti Chang Sun, Na Liu, Jue Kou, Ya Na Ji, Yan Xu e Yu Xia Wei. "Mechanism Research on Niobium Distribution Influenced by Roasting Temperature in the Direct Reduction Roasting Process". Advanced Materials Research 634-638 (gennaio 2013): 3416–22. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.3416.

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Abstract (sommario):

In this study, the niobium enrichment research of the iron concentrate containing niobium was studied by coal-based direct reduction roasting followed by magnetic separation process. The distribution of niobium element and existence form of mineral bearing-Nb in roasted products were investigated under different roasting temperature which was ranging from 1100°C to 1300°C. X-ray diffraction analysis (XRD) was used to identify the various minerals and compositions of the roasted products. The microstructures of these products were analyzed by the scanning electron microscope (SEM), while the elemental analysis was carried out by using energy dispersive spectrometer (EDS) technique. The results of XRD and EDS analysis showed that most of the niobium minerals were Nb-Fe rutile and ulvospinel which scattered in slag, and only a little was adhered to the surface of metallic iron at 1100°C. And the niobium oxides were partly reduced to Ti-aeschynite and niobocarbide which attached on the surface of metallic iron, and most were still ulvospinel scattering in the slag at 1200°C. The Ti-aeschynite was gradually reduced to Nb adhering to the metallic iron particle forming Nb-Fe soild solution at 1300°C.

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Korol, Dmytro, Artem Yefimenko e Mykhailo Korol. "COMPARISON OF THE CONDITION OF THE PERI-IMPLANT ORAL MUCOUS ACCORDING TO THE RESULTS OF DIGITAL MICROSCOPY". ScienceRise, n. 6 (30 dicembre 2020): 68–73. http://dx.doi.org/10.21303/2313-8416.2020.001558.

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The object of the study there is a level of hyperemia of the mucous membrane around the installed intraosseous dental implants with different coating material according to the results of histogram analysis of digital microscopy. The problem to be solved – evaluation of the degree of hyperemia of the periimplant mucosa around intraosseous dental implants coated with rutile, in comparison with titanium implants of VT-6 alloy after prosthetics. Main scientific results: Analysis of digital images using histogram evaluation of the red component of the spectrum showed that 1 month after prosthetics in group 1, which included 20 patients who had intraosseous implants made of titanium alloy TiV6Al (VT-6), the above indicator increased to 191 (St.Err. 4.45). The difference was 4 conventional units. Similarly, in group 2 (16 people) who had intraosseous zirconium implants, there was an increase in the quantitative rate after prosthetics by 9 conventional units, and its value was 194 conventional units (St.Err. 3.64). Since increasing numerical values and shifting the digital histogram to the right is an objective criterion for reducing the intensity of redness, it can be concluded that there is a reduction of mucosal irritation after orthopedic treatment with a predominance of this process in the group of patients who received intraosseous dental implants coated with rutile. The area of practical use of research results: Since the authors first studied the reaction of the peri-implant mucosa in contact with various implant materials at the stages of orthopedic treatment, this is the basis for the introduction into general medical practice of intraosseous dental implants made in Ukraine using rutile application technology. The area of application of an innovative technological product - it is a dental implant practice. The obtained results will allow to use more widely Ukrainian implants of non-demountable construction with a high level of surface preparation, for the purpose of further orthopedic treatment with the use of non-removable metal-ceramic dentures.

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Zhou, Song, Yu Cheng Wu, Jun Lv, Ling Kun Guo, Dong Mei Wang, Guang Qing Xu e Zhi Xiang Zheng. "Research on Photocatalysis Properties of Nano TiO₂/Mica Composite Material Prepared by the Method of Hydrolysis–Precipitation". Materials Science Forum 694 (luglio 2011): 449–55. http://dx.doi.org/10.4028/www.scientific.net/msf.694.449.

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Using muscovite as the carrier, TiCl4 as the source of titanium, urea as the precipitating agent, nano-TiO2/mica photocatalyst (TiO2/M) was prepared by the method of hydrolysis–precipitation. The as - prepared photocatalyst was characterized by XRD, SEM, EDS and UV methods. The methyl orange was used as contamination simulation to test the photocatalytic activity of the materials. The influence of the calcination temperature, radiation time and photocatalyst adding amount on photocatalytic activity of methyl orange were also discussed. The SEM and XRD results showed that nano-TiO2 particles had been evenly coated on the muscovite surface to be a dense layer. The results showed that: the phases of as – prepared materials were mixed crystalline of anatase and rutile after calcinating from 400°C to 700°C; After calcinating at 400°C for 2h, and adding concentration was 2g/L, the material had the best photocatalytic activity, the degradation rate of methyl orange reached 98% after radiation under 300W mercury lamp for 60min.

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Music, Denis, Andreas M. Krause e Pär A. T. Olsson. "Theoretical and Experimental Aspects of Current and Future Research on NbO2 Thin Film Devices". Crystals 11, n. 2 (22 febbraio 2021): 217. http://dx.doi.org/10.3390/cryst11020217.

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Abstract (sommario):

The present research front of NbO2 based memory, energy generation, and storage thin film devices is reviewed. Sputtering plasmas contain NbO, NbO2, and NbO3 clusters, affecting nucleation and growth of NbO2, often leading to a formation of nanorods and nanoslices. NbO2 (I41/a) undergoes the Mott topological transition at 1081 K to rutile (P42/mnm), yielding changes in the electronic structure, which is primarily utilized in memristors. The Seebeck coefficient is a key physical parameter governing the performance of thermoelectric devices, but its temperature behavior is still controversial. Nonetheless, they perform efficiently above 900 K. There is a great potential to improve NbO2 batteries since the theoretical capacity has not been reached, which may be addressed by future diffusion studies. Thermal management of functional materials, comprising thermal stress, thermal fatigue, and thermal shock, is often overlooked even though it can lead to failure. NbO2 exhibits relatively low thermal expansion and high elastic modulus. The future for NbO2 thin film devices looks promising, but there are issues that need to be tackled, such as dependence of properties on strain and grain size, multiple interfaces with point and extended defects, and interaction with various natural and artificial environments, enabling multifunctional applications and durable performance.

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LV, Yingli, Qui-Thao Le, Hoang-Bac Bui, Xuan-Nam Bui, Hoang Nguyen, Trung Nguyen-Thoi, Jie Dou e Xuan Song. "A Comparative Study of Different Machine Learning Algorithms in Predicting the Content of Ilmenite in Titanium Placer". Applied Sciences 10, n. 2 (16 gennaio 2020): 635. http://dx.doi.org/10.3390/app10020635.

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Abstract (sommario):

In this study, the ilmenite content in beach placer sand was estimated using seven soft computing techniques, namely random forest (RF), artificial neural network (ANN), k-nearest neighbors (kNN), cubist, support vector machine (SVM), stochastic gradient boosting (SGB), and classification and regression tree (CART). The 405 beach placer borehole samples were collected from Southern Suoi Nhum deposit, Binh Thuan province, Vietnam, to test the feasibility of these soft computing techniques in estimating ilmenite content. Heavy mineral analysis indicated that valuable minerals in the placer sand are zircon, ilmenite, leucoxene, rutile, anatase, and monazite. In this study, five materials, namely rutile, anatase, leucoxene, zircon, and monazite, were used as the input variables to estimate ilmenite content based on the above mentioned soft computing models. Of the whole dataset, 325 samples were used to build the regarded soft computing models; 80 remaining samples were used for the models’ verification. Root-mean-squared error (RMSE), determination coefficient (R2), a simple ranking method, and residuals analysis technique were used as the statistical criteria for assessing the model performances. The numerical experiments revealed that soft computing techniques are capable of estimating the content of ilmenite with high accuracy. The residuals analysis also indicated that the SGB model was the most suitable for determining the ilmenite content in the context of this research.

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Serga, Vera, Regina Burve, Aija Krumina, Marina Romanova, Eugene A. Kotomin e Anatoli I. Popov. "Extraction–Pyrolytic Method for TiO2 Polymorphs Production". Crystals 11, n. 4 (16 aprile 2021): 431. http://dx.doi.org/10.3390/cryst11040431.

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The unique properties and numerous applications of nanocrystalline titanium dioxide (TiO2) are stimulating research on improving the existing and developing new titanium dioxide synthesis methods. In this work, we demonstrate for the first time the possibilities of the extraction–pyrolytic method (EPM) for the production of nanocrystalline TiO2 powders. A titanium-containing precursor (extract) was prepared by liquid–liquid extraction using valeric acid C4H9COOH without diluent as an extractant. Simultaneous thermogravimetric analysis and differential scanning calorimetry (TGA–DSC), as well as the Fourier-transform infrared (FTIR) spectroscopy were used to determine the temperature conditions to fabricate TiO2 powders free of organic impurities. The produced materials were also characterized by X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). The results showed the possibility of the fabrication of storage-stable liquid titanium (IV)-containing precursor, which provided nanocrystalline TiO2 powders. It was established that the EPM permits the production of both monophase (anatase polymorph or rutile polymorph) and biphase (mixed anatase–rutile polymorphs), impurity-free nanocrystalline TiO2 powders. For comparison, TiO2 powders were also produced by the precipitation method. The results presented in this study could serve as a solid basis for further developing the EPM for the cheap and simple production of nanocrystalline TiO2-based materials in the form of doped nanocrystalline powders, thin films, and composite materials.

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47

SAIDOV, RUSTAM, RUSTAM RAKHIMOV, BEKZOD YUSUPOV e MUHAMMAD KHOLDOROV. "EFFICIENCY OF DRYING AND CALCINING OF WELDING ELECTRODES IN FURNACES USING RADIATION FROM NANOSTRUCTURED FUNCTIONAL CERAMICS (NFC)". Computational nanotechnology 7, n. 2 (30 giugno 2020): 64–70. http://dx.doi.org/10.33693/2313-223x-2020-7-2-64-70.

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This article presents the results of research on the influence of various methods of drying and calcining welding electrodes coated with acid-rutile type standard technology in electric furnaces and in furnaces using nanostructured functional ceramics (NFC) radiation on the welding and technological properties of welding electrodes. According to the results of research, the improvement of welding and technological properties during the drying and calcining of welding electrodes in a furnace using radiation with NFC was revealed. Calcination of welding electrodes using NFC radiation allows to obtain high-quality welding and technological properties of coatings without the use of natural drying after coating the welding wire. This makes it possible to perform heat treatment of welding electrodes with great savings in power consumption and reduced calcination time compared to standard technology.

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48

Ma, Tian, Yong Huang, Jin Long Yang, Li Ming Zhang e L. Zhao. "Preparation of High Capacity Thin-Wall Rutile Tube for Ozone Generator by Colloidal Injection Moulding of Ceramics". Key Engineering Materials 280-283 (febbraio 2007): 1163–66. http://dx.doi.org/10.4028/www.scientific.net/kem.280-283.1163.

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Colloidal injection moulding of ceramics (CIMC), an innovative technique combining the advantages of conventional injection moulding and colloidal forming process, is applied to prepare thin-wall rutile tube for high capacity ozone generator. The forming process is studied detailed and the processing parameter of forming, drying and sintering schedule is determined in this research. The wall thickness of the sintered tube is 1.5~2mm and its inner diameter is about 26 mm, length is about 300 mm. The electric properties of the tube are also measured under different conditions. The above-mentioned tube is applied in ozone generator and the yield of ozone is about 55mg·L-1.

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49

Clarissa, Devara, Bambang Priyono, Ahmad Maksum, Memed Sumantono e Johny Wahyuadi Soedarsono. "Analysis effect of temperature on the results of titanomagnetite (Fe2TiO4-Fe3O4) formation in iron sand reduction using coal and sodium sulphate as an additive". E3S Web of Conferences 67 (2018): 03056. http://dx.doi.org/10.1051/e3sconf/20186703056.

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Indonesia is a developing country that has rich deposit of natural resources particularly in mineral ores. Many of iron sand found in coastal Indonesia that contains some valuable minerals such as hematite (Fe2O3), ilmenite (FeTiO3) sand rutile (TiO2). Research study related to iron sand has developed that aims to determine the effect of temperature against the form of titanomagnetite in reduction process using coal as reductor and sodium sulphate (Na2SO4) as an additive. The results of XRD characterization and semi- quantitative with temperature variable 700°C, 800°C and 900°C obtained that 900°C is an optimum temperature with amount of titanomagnenite (Fe2TiO4-Fe3O4) as much as 48.5.

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50

Zhang, Shu Juan, Ming Sheng Li, Zhi Qin Chen e Yong Zhong Fan. "The Research of the C-Doped TiO₂ Films Deposited by Arc Ion Plating". Applied Mechanics and Materials 182-183 (giugno 2012): 292–96. http://dx.doi.org/10.4028/www.scientific.net/amm.182-183.292.

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The uniform and transparent C-doped TiO2thin films were successfully deposited on medical glass slide by arc ion plating. The influences of the C-doped quantity, pulsed negative bias and annealing treatment on films properties were investigated. Film structure, surface morphologies and optical properties were measured with XRD, SEM and UV-VIS transmittance spectroscope. Photo-catalytic performance of the films was evaluated by degrading methyl orange. The results show that the C-doped quantity and annealing treatment have important influence on the absorption edges. The effect of annealing treatment is similar to that of the increasing the C-doped quantity, and they can enhance the C doping and extends the absorption edge. The absorption edges of the films increase with the rising of the C-doped quantity, and all the films absorption edges increase after annealing at 400°Cfor 4h, and the best extending can increase 20nm after annealing. Along with the negative bias increasing, the intensity of rutile diffraction peak increases, but the anatase decreases. The micro-morphology and crystal structure of different C-doped quantity are mutually correspond. The roughness and grain size of TiO2films surface decreases significantly with the negative bias increasing. The crystal grains become even and fine, the high bias films surface micro-morphology has rice-like granular shape.

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