•Surface modification pretreatment on the laser joint of COP and SUS304 was studied.•Joint strength of the surface-modified COP and SUS304 was significantly improved.•UV–ozone processing generated ...noticeably more bubbles than plasma pretreatment.•Excessive surface-modification pretreatment for COP decreased the joint strength.•COP surface energy of 55–65mJ/m2 at room temperature gave highest joint strength.
Surface modification pretreatment on the laser-bonded joint between a cyclic olefin polymer (COP) and stainless steel (SUS304) was studied to determine its effect on improving the laser-bonded joint strength. The joint strength between the surface-modified COP and SUS304 was significantly improved compared with that of an equivalent un-treated joint. This improvement is caused by the generation of oxygen functional groups on the COP surface resulting in the improved adhesion of these groups with the oxide film formed on the SUS304 surface.
As for the surface pretreatment of COP, the generation of bubbles in ultraviolet (UV)–ozone processing due to thermal degradation of the COP was more noticeable than with plasma pretreatment. Excessive surface modification of the COP, causing a decrease in joint strength was found to correlate with the surface energies of COP and SUS304.
Chromite is a typical refractory igneous mineral, precipitated from mafic magmas at relatively high temperatures. Chromites commonly occur in sedimentary, metamorphic, and metasomatic rocks, where ...they are interpreted as relics of an igneous phase and serve as the source of Cr for low-temperature Cr-bearing minerals. We present evidence for the nucleation of chromite within hydrothermal solutions. We have found minute euhedal chromite grains enclosed by uvarovite (Ca-Cr garnet) in a diopsidite, metasomatically replacing the layered gabbro of the Oman ophiolite. The uvarovite shows oscillatory concentric zoning in terms of Cr no. Cr/(Cr+Al), and the chromite is embedded only in the high-Cr-no. zones of the uvarovite. Another diopsidite, replacing peridotite in the underlying upper mantle section, contains xenocrystic chromite, which is partly dissolved. This suggests that a hydrothermal solution collected Cr by partial to total dissolution of chromite within the upper mantle and precipitated chromite, along with high-Cr-no. uvarovite, within the lower crust upsection. The metasomatic agent involved was a CO2-, SO2-, and Cl-bearing hydrothermal solution containing appreciable silicate components that could carry Cr, possibly as a complex. The hydrothermal chromite is similar in chemistry to that commonly found in igneous rocks e.g., Cr no. = 0.8, Mg/(Mg+Fe2+) = 0.1-0.2, TiO2 < 0.3 wt% and Fe3+/(Cr+Al+Fe3+), up to 0.3, but its Cr no. is clearly different from that of mantle chromite (0.6-0.7) in peridotites and chromitites from the Oman ophiolite. The results from this study suggest that a hydrothermal origin is possible for chromites in ultramafic rocks that have experienced fluid activity assuming that there is sufficient chromite at the fluid source.
Mechanical fatigue in silicon was discovered in 1992, but the mechanism by which it takes place has yet to be clarified. To determine the fatigue mechanism, a new testing structure was developed and ...optimized for investigation by high-voltage transmission electron microscopy (HVTEM). After 5 × 10
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fatigue cycles at 25 °C and 80% relative humidity (RH), the entire thickness of the fractured specimen was examined directly by HVTEM without applying a thinning process, which eventually shaves off part of the material to be observed. The investigation revealed a number of line defects emanating from the stress concentration notch that accumulated on particular planes and also from the points beside the origin of the unstable crack extension. Those defects were identified as edge dislocations moving along the slip plane {111} in the slip direction , which is typical of the silicon slip system. Therefore, our findings strongly suggest that mechanical fatigue fracture takes place in silicon owing to dislocations moving under repeated loading, even at approximately 25 °C, i.e., room temperature, in the same way as in metallic materials.
Background Renal cell cancer and malignant melanoma are two types of cancer that are responsive to immunotherapy. In this phase I dose-escalation study, the feasibility of large-scale expansion and ...safety of administering ex vivo -expanded NK-92 cells as allogeneic cellular immunotherapy in patients with refractory renal cell cancer and melanoma were determined. Methods Twelve patients (aged 31–74 years) were enrolled, three per cohort at cell dose levels of 1 × 108 /m2 , 3 × 108 /m2 , 1 × 109 /m2 and 3 × 109 /m2 . One treatment course consisted of three infusions. Eleven patients had refractory metastatic renal cell cancer; one patient had refractory metastatic melanoma. Results The NK-92 cells were expanded in X-Vivo 10 serum-free media supplemented with 500 U/mL Proleukin recombinant human interleukin-2 (rhIL-2), amino acids and 2.5% human AB plasma. Final yields of approximately 1 × 109 cells/culture bag (218–250×expansion) over 15–17 days were achievable with ≥80% viability. Infusional toxicities of NK-92 were generally mild, with only one grade 3 fever and one grade 4 hypoglycemic episode. All toxicities were transient, resolved and did not require discontinuation of treatment. One patient was alive with disease at 4 years post-NK-92 infusion. The one metastatic melanoma patient had a minor response during the study period. One other patient exhibited a mixed response. Discussion This study establishes the feasibility of large-scale expansion and safety of administering NK-92 cells as allogeneic cellular immunotherapy in advanced cancer patients and serves as a platform for future study of this novel natural killer (NK)-cell based therapy.
High thermal conductivity Cu/diamond composites were produced at ambient temperature and pressure using an electrodeposition technique, employing various diamond particle sizes in the range of 10 to ...230 μm. The microstructures of the resulting composites were analyzed by scanning electron microscopy and their thermal conductivities were assessed using a Xenon flash instrument. The theoretical thermal conductivities of these materials were calculated based on the Hasselman-Johnson equation and compared with the experimentally determined values. The Cu/diamond composites produced in this work were found to exhibit compact textures without any gaps between the Cu matrix and the diamond particles, and the experimental thermal conductivities were in good agreement with the theoretical values. The specimen containing 61 vol.% of 230 μm diameter diamond particles had the highest conductivity of 662 W K-1 m-1, which is 1.6 times that of pure Cu (ca. 400 W K-1 m-1).
There is an old Chinese thought meaning that medicine and food are isogenic. In Japan, a national research project started to endorse the thought scientifically, with the birth of functional foods ...that are now known to function to reduce the risk of life-style related diseases. The science gave rise to a national policy in which some functional foods were legally approved in terms of Foods for Specified Health Use. China has also constructed a unique system for approving some functional foods. This paper pinpoints a recent trend of functional foods characteristic to Asia, with special reference to relevant topics in Japan.
•Influences of build direction/laser conditions (30-wt%-SGF specimens) were evaluated.•Fiber orientation is ordered as roller-movement, vertical, and thickness directions.•Significant influence of ...fiber orientation on various properties was observed.•Double-scan method improved mechanical and thermal properties.•Shrinkage differs in the cases of single- and double-scan scanning.
Copolymer poly(butylene terephthalate) with 30- wt% short glass fiber (SGF) added was used to evaluate the dependence of the properties of specimens manufactured by selective laser sintering (SLS) and the influence of laser-irradiation conditions on build direction. The degree of orientation of SGFs in SLS is ranked in descending order of roller-movement direction, vertical direction in the powder-bed plane, and direction of lamination-layer thickness. Moreover, the influence of fiber orientation on mechanical properties, thermal properties, and shrinkage ratio was found to be remarkable. In the case of the double-scan method, in comparison to the single-scan case, while thermal degradation was suppressed, porosity was reduced, and mechanical properties were improved. In addition, degree of crystallinity of the SLS specimens increased, and heat-deflection temperature increased slightly. Furthermore, in regard to roller-movement direction and lamination-layer thickness direction, the trends of shrinkage ratio differ in the cases of the single- and double-scan scanning methods.
Abstract
Weakly nonlinear (i.e., finite but small amplitude) propagation of plane progressive pressure waves in compressible water flows uniformly containing many spherical bubbles is theoretically ...studied. Drag force acting bubbles and translation of bubbles are newly considered by introducing in momentum conservation equations in a two fluid model and the bubble dynamics equation for volumetric oscillations, respectively. Although these assumptions are the same as our previous paper, in this study, the energy conservation equation for each bubble describing a thermal conduction inside bubble is introduced. By using the method of multiple scales, the Korteweg–de Vries–Burgers equation for low-frequency long wave was derived from the set of basic equations in the two-fluid model. As a result, the dissipation effect was described by two types of terms, i.e., one was the second-order partial derivative owing to the liquid compressibility and the other was the term without differentiation owing to the drag force and the thermal conduction. Finally, we clarified that the dissipation owing to the drag force was smaller than that owing to the thermal conduction.
With proportion of short-glass-fiber (SGF) addition (15, 30, 45, and 60 wt%) taken as a parameter, the powder properties of composite-copolymer poly(butylene terephthalate) (cPBT) powder and various ...properties of the cPBT-SGF specimens manufactured by selective laser sintering (SLS) were evaluated. Even in the case that SGF was added, the flowability of the powder was dramatically improved by adding silica to it. Moreover, as the proportion of added SGF was increased, the flowability was degraded. In the case proportion of SGF addition was taken as a parameter, tensile strength and flexural strength of the SLS specimen were maximized by SGF addition of 30 wt%; however, impact strength was maximized by SGF addition of 45 wt%. As the proportion of added SGF was increased, the amount of SGF “debonding” also increased, while the amount of resin that adheres to the SGFs decreased and porosity increased. In addition, the average glass-fiber length of the SLS specimens decreased with the addition of 45-wt% SGF, whereas it did not decrease with addition of 30-wt% SGF. Furthermore, in contrast to long fibers easily aligning and remaining in the direction of the roller, SGFs did not align in the direction of layer-thickness. Compared to SGF addition having an insignificant effect on mechanical properties, it significantly improved thermal properties (i.e., heat deflection temperature and linear-expansion coefficient) and reduced shrinkage. Moreover, even if SGF was added, it had little effect on the crystallization properties of the powder and SLS-formed specimen.
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