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• Lubrication analysis considered the slope parameter of the friction surface and surface roughness. • Relative slope of the pad bearing surface is confirmed to influence the friction characteristics. • Fluid film thickness is calculated by analyzing the slope parameter obtained from the friction tests. • Experimental values of friction coefficient and slope parameter are compared with numerical analysis. • Measured results were to verify lubrication analysis results of tilting pad bearings. Researchers studying lubrication analysis have investigated both mixed and hydrodynamic lubrication. Lubrication analysis has been considered with respect to the slope parameter of the friction surface and surface roughness. Furthermore, the relative slope of the pad bearing surface was confirmed to influence friction characteristics. However, whether the lubrication analysis values are comparable to those obtained via friction tests has remained unclear. In this study, we developed an experimental device to obtain the slope parameter and analyzed the results to experimentally verify the lubrication analysis results. The fluid film thickness was calculated by analyzing the slope parameter obtained from the friction tests, and was used as the input value for the lubrication analysis. Thereafter, the experimental values of the friction coefficient and slope parameter were compared with those obtained via numerical analysis. [ABSTRACT FROM AUTHOR]

The phase junction of TiO2 nanoparticles plays an essential role in improving photocatalytic activity. Mixed phase brookite–rutile TiO2 nanoparticles with different phase compositions were synthesized through a hydrolysis method using nitric acid of different concentrations. The bi-crystalline phase was characterized by X-ray diffraction (XRD), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and Brunauer–Emmett–Teller (BET), UV-vis diffuse reflectance spectroscopy (DRS) and Photoluminescence (PL) analysis. Photoelectrochemical properties were investigated by transient photocurrent density (TPR) and electrochemical impedance spectroscopy (EIS). XRD and Raman results revealed that the brookite content increased in the sample when increasing the HNO3 concentration. The prepared mixed-phase TiO2 nanoparticles have mesopores with large surface areas ranging from 48.81 to 89.95 m2 g−1. UV-vis spectra showed a redshift of absorption edge from 398 nm to 408 nm with increasing brookite content. The optical band gaps which were obtained from the UV-vis spectra were decreased with increasing brookite content. Photoluminescence results showed that the sample prepared with 5.0 M nitric acid (BCTi-4) showed the lowest emission due to the electron–hole recombination. Furthermore, BCTi-4 revealed the highest photocurrent density of 6 μA cm−2 and the smallest Rct values of 3.30 kΩ. The photocatalytic properties of prepared samples were evaluated by the degradation of methylene blue under UV and visible light irradiation. The BCTi-4 exhibited the highest degradation rate that completely degraded methylene blue after 3 hours of UV irradiation and 36 hours under visible light irradiation. This was attributed to the synergetic effect of phase junction of brookite and rutile, which reduces the recombination of photoexcited electron–hole pairs and the optimal ratio of brookite and rutile. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cemented carbide-PCD microdrills were fabricated through brazing technique. • Average axial straightness error of both microdrills were less than 2 μ m. • Radial runout measured at tool tip was greater than the measurement at drill body. • Standard deviation and repeatability of measurements were ± 0.6 μ m and ± 1.3 μ m. Microdrill machining is in high demand and is widely applied in various industries where the structural design and material properties of the microdrill are critical components in machining. A composite microdrill composed of cemented carbide and polycrystalline diamond balances the wear resistance, toughness, and hardness properties of the cutting tool. Nevertheless, the tool geometry error must be examined because of complex technique involved in the tool fabrication process. The investigated microdrill is fabricated through a brazing technique that connects the shank and drill body of different material compositions. A computer vision algorithm was developed specifically for measuring the axial straightness error and radial runout of the microdrill. Accordingly, the ability of the developed measurement techniques to perform precise and accurate tool geometry error measurements is evaluated in this study. [ABSTRACT FROM AUTHOR]

Jin S-M, Shin JS, Kim KS, Gong C-H, Park SK, Kim J-S, Yeom S-C, Hwang ES, Lee CT, Kim S-J, Park C-G. Islet isolation from adult designated pathogen-free pigs: use of the newer bovine nervous tissue-free enzymes and a revised donor selection strategy would improve the islet graft function. Xenotransplantation 2011; 18: 369-379. © 2011 John Wiley & Sons A/S. Abstract: Background: In clinical trials using adult porcine islet products, islets should be isolated from the designated pathogen-free (DPF) pigs under the current good manufacturing practice (GMP) regulations. Our previous studies suggested that male DPF pigs are better donors than retired breeder pigs and histomorphometrical parameters of donor pancreas predict the porcine islet quality. We aimed to investigate whether the use of the newer bovine nervous tissue-free enzymes and a revised donor selection strategy could improve the islet graft function in the context of islet isolation with DPF pigs. Methods: Using 30 DPF pigs within a closed herd, we compared the islet yield of porcine islets isolated with Liberase PI (n = 11, as a historical control group), Liberase MTF C/T, which is a GMP-grade enzyme (n = 12), and CIzyme collagenase MA/BP protease (n = 7). We analyzed the relationship between the diabetes reversal rate of recipient NOD/SCID mice (n = 75) and histomorphometric parameters of each donor pancreas as well as donor characteristics. Results: Proportion of islets larger than 200 μm from the biopsied donor pancreas (P = 0.006) better predicted islet yield than age (P = 0.760) or body weight (P = 0.371) of donor. The proportion of islets larger than 200 μm from the biopsied donor pancreas was not related to the sex of the donor miniature pig (P = 0.358). The islet yield obtained with the three enzymes did not differ, even after stratification of the donor with the histomorphometric parameters of the biopsied donor pancreas and the sex of donor. The use of the newer bovine nervous tissue-free enzymes (P < 0.001), a higher proportion of large islets in donor pancreas (P = 0.006), and a male sex of the donor (P = 0.025) were independent predictors of earlier diabetes reversal. Conclusions: Use of the newer bovine nervous tissue-free enzymes including a GMP-grade enzyme resulted in better islet quality than that of islet isolated using Liberase PI. To obtain high-quality islet from DPF pigs, the donor should be male pig and histomorphometrical parameters from donor pancreas should be considered. [ABSTRACT FROM AUTHOR]

Abstract In this study, we synthesized porphyrin dyes and structurally characterized them using 1H and 13C NMR and FT-IR and high-resolution mass spectrometry. By using these porphyrins, new TiO 2 -porphyrin catalysts (TiO 2 -PORPC-1 , TiO 2 -PORPC-2, TiO 2 -PORPC-3 and TiO 2 -PORPC-4), were prepared and the structures of these catalysts were confirmed by using SEM, TEM, solid-state UV-visible spectroscopy, XPS, FT-IR spectroscopy and EDS analysis. Studies on the photodegradation of methylene blue suggested that our TiO 2 -porphyrin photocatalysts were more effective for the degradation than bare TiO 2 -anatase, and furthermore, TiO 2 -Zn-porphyrins showed better photocatalytic activity than the metal-free TiO 2 -porphyrins because of their high charge-transfer properties. We evaluated the stability of the TiO 2 -porphyrins by repeatability test. Finally, we proposed a plausible mechanism for the photocatalytic activity. Graphical abstract Image 1 Highlights • Novel TiO 2 -porphyrin catalysts were prepared and characterized. • Photocatalysts showed high activity in Methylene Blue (MB) degradation. • TiO 2 -porphyrin photocatalysts were more effective than bare TiO 2 -anatase. • TiO 2 -Zn-porphyrins showed better activity than nonmetalated TiO 2 -porphyrins. • The plausible photocatalytic mechanism was projected. [ABSTRACT FROM AUTHOR]