Vibrational spectroscopic imaging has become useful analytical tools for quality control of drug products. In this study, we applied microscopic attenuated total reflection (ATR)-IR and confocal ...Raman microscopy to elucidate microscopic structure of creams and for the formulation design in the development of semi-solid drug products. The model creams were prepared with prednisolone (PRD) and fluconazole (FLC) as active pharmaceutical ingredients and oily solvents such as mineral oil (MO), isopropyl myristate (IPM), benzyl alcohol (BA) and diethyl sebacate (DES). As a result of microscopic ATR-IR imaging, several domains indicating oily internal phase were observed, which had absorption around 1732 and 1734 cm−1 derived from MO, IPM and DES. In addition, domains of BA around 1009 cm−1 were observed at the complemental or similar position in the formulation with MO or DES, respectively. These results suggested that the creams were oil-in-water type and the distribution of domains would reflect the compatibility of the solvents. The contents of PRD and BA were determined quantitatively in each layer after the intentional separation of the creams and the results agreed well with the imaging analysis. Whereas, confocal Raman imaging allowed to visualize the distribution of the components in depth direction as well as two-dimensional plane. In particular, the Raman imaging would ensure the coexistence of FLC and BA as oily phase in the cream. From these results, the feasibility of spectroscopic imaging techniques was successfully demonstrated for the formulation design of semi-solid dosage forms.
The adsorption behavior of energy-related gases onto ZIF-8 was investigated using terahertz waves. Comparison of the terahertz transmission spectra of ZIF-8 before and after exposure to the gases ...revealed that the 2 THz vibrational mode was involved in the gate-opening motion of organic linker molecules. The adsorption properties of each gas were detailed by monitoring the intensities of the 2 THz absorption peak.
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IJS, KILJ, NUK, PNG, UL, UM
Finite element analyses of the propagation of damage such as fiber compressive failure and delamination have greatly contributed to the understanding of failure mechanisms of fiber-reinforced ...plastics owing to extensive studies on methodologies using Continuum Damage Mechanics and Fracture Mechanics. Problems without the need for consideration of inertia, such as Double-Cantilever Beam tests, are usually solved by implicit FE solvers, and explicit FE solvers are appropriate for phenomena that progress with very high velocity such as impact problems. However, quasi-static problems with unstable damage propagation observed in experiments such as Open-Hole Compression tests are still not easy to solve for both types of solvers. We propose a method to enable the static FE solver to solve problems with unstable propagation of damage. In the present method, an additional process of convergence checks on the averaged energy release rate of damaged elements is incorporated in a conventional Newton–Raphson scheme. The feasibility of the present method was validated by two numerical examples consisting of analyses of Open-Hole Compression tests and Double-Cantilever Beam tests. The results of the analyses of OHC tests showed that the present method was applicable to problems with unstable damage propagation. In addition, the results from the analyses of DCB tests with the present method indicated that mesh density and loading history are not significantly influential to the solution.
In accordance with the results of our previous research, a low-temperature growth (LTG) technique is effective for expanding the lower growth temperature region of c-axis-orientated SmBa2Cu3Oy ...(SmBCO) thin films. However, BaHfO3 (BHO)-doped LTG films show a marked decrease in Jc at low magnetic fields compared with conventional PLD films. In this study, we aimed to clarify the mechanism of Jc decrease and investigated the thickness dependence of the seed layer on the (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) (100) single crystal. The obtained results indicate that Jc decreased at low magnetic fields as the thickness of the seed layer increased. It is suggested that flux line kinks produced by flux motion in the seed layer would lead to the depinning of flux lines from BHO nanorods in the upper layer. Thus, we added Y2O3 into the seed layer to trap flux lines in the seed layer. Consequently, we improved Jc in the low magnetic field region even in the films prepared by using the LTG technique.
It is important to further improve the traveling performances of the moon/planetary exploration rovers. To achieve this, we investigated the grouser shape of rigid wheels for use in such rovers, ...focusing particularly on rectangular and trapezoidal grousers. First, simple intrusion tests were carried out using the discrete element method. Grousers having a trapezoidal cross-sectional shape exerted a "packing effect" through which particles between grousers were strongly compressed. Next, single-wheel experiments were conducted, and the results show that sinkage was suppressed by the trapezoidal-shaped grousers. In addition, it was confirmed that trapezoidal-shaped grousers exhibited a drawbar-pull equivalent to that generated by the widely used rectangular-shaped grousers. Furthermore, we performed theoretical analysis using the resistive force theory to clarify the packing effect, and the results indicate that the use of a wheel with a trapezoidal-shaped grouser could be an effective method to improve the traveling performance of a rigid wheel.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
•Effectiveness of an extended terramechanics model was examined.•Traveling performance of a rover was evaluated.•Model accurately represented drawbar pull and sinkage in forced-slip condition.•It ...reproduced difference in traveling performance in self-propelled condition.•Model can be used in the design of rovers and wheels.
The evaluation of the traveling performance of moon/planetary exploration rovers is the primary aspect of scientific missions and human exploration in space. However, conventional models lack the detailed description of mechanical interaction between the wheels and soft soil. Therefore, in this study, the effectiveness of an extended terramechanics (xTerramechanics) model was investigated by considering the soil deformation actions based on cellular automata for the evaluation of rover traveling performance. First, the results of single-wheel traveling analysis were compared with the experimental results under the forced-slip condition, and it was shown that drawbar-pull and sinkage were represented with good accuracy (mean absolute errors less than 5.5 N and 3.2 mm). Next, we applied the xTerramechanics model under the self-propelled traveling condition at a constant towing load and slope climbing. The model successfully reproduced the well-known “difference in traveling performance depending on traveling conditions.” Furthermore, we used the model for the multibody dynamics analysis of a simple rover, and its applicability to the examination of the overall vehicle performance and multipath effects was demonstrated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We have reported that a low temperature growth (LTG) technique is effective to expand the lower growth temperature region of c-axis orientated SmBa2Cu3Oy (SmBCO) thin films so far. However, BaHfO3 ...(BHO)-doped SmBCO LTG-films show serious decrease of Jc at low magnetic field compared with conventional PLD-films. We investigated thickness dependence of SmBCO seed layers on LSAT single crystal. The result shows the seed layer is the cause of Jc decrease at low magnetic field due to flux line motion in the seed layer. In order to prevent the Jc decrease, we have tried to add Y2O3 in the seed layer on IBAD-MgO substrate. As a result, Sm-rich particles were formed in the seed layer, and those particles prevented flux line motion in the seed layer. After that, we measured the BHO-doped SmBCO films on Y2O3-doped seed layer at 77 K. As a result, the Y2O3-doped seed layer is effective at 77 K because the diameter of Sm-rich particle is about 17 nm which is larger than coherent length of 77 K in REBCO films. In summary, we improved Jc decrease at low magnetic field by adding the Y2O3 in the seed layer, and that film deposited by PLD-LTG technique showed high Jc at wide magnetic field.
This paper presents stress singularity analysis using three-dimensional Akin singular element. In case that Akin singular element is employed, it is necessary to know order of singularity before ...stress analysis. However, in case of three-dimensional model, it is not easy to obtain order of singularity comparing to 2-dimensional model. Therefore, a finite element eigen analysis is applied to obtain order of singularity in 3-dimensional bonded structure model, and the obtained order of singularity is applied to Akin singular element. This analysis is frequently applied to obtain 3-dimensinal order of singularity. Consequently, it was found that order of singularity obtained by least square approximation is close to that obtained by the finite element eigen analysis comparing to that in case of normal element. Furthermore, it was found that convergence process in conjugate gradient method is almost same between normal and singular elements in case that course mesh is used around singular point. On the other hand, it was found that it takes a lot of iterations in case of use of singular element if fine mesh is employed around singular point.
Vibrational spectroscopic imaging has become useful analytical tools for quality control of drug products. In this study, we applied microscopic attenuated total reflection (ATR)-IR and confocal ...Raman microscopy to elucidate microscopic structure of creams and for the formulation design in the development of semi-solid drug products. The model creams were prepared with prednisolone (PRD) and fluconazole (FLC) as active pharmaceutical ingredients and oily solvents such as mineral oil (MO), isopropyl myristate (IPM), benzyl alcohol (BA) and diethyl sebacate (DES). As a result of microscopic ATR-IR imaging, several domains indicating oily internal phase were observed, which had absorption around 1732 and 1734 cm-1 derived from MO, IPM and DES. In addition, domains of BA around 1009cm-1 were observed at the complemental or similar position in the formulation with MO or DES, respectively. These results suggested that the creams were oil-in-water type and the distribution of domains would reflect the compatibility of the solvents. The contents of PRD and BA were determined quantitatively in each layer after the intentional separation of the creams and the results agreed well with the imaging analysis. Whereas, confocal Raman imaging allowed to visualize the distribution of the components in depth direction as well as two-dimensional plane. In particular, the Raman imaging would ensure the coexistence of FLC and BA as oily phase in the cream. From these results, the feasibility of spectroscopic imaging techniques was successfully demonstrated for the formulation design of semi-solid dosage forms.
The simultaneous process of synthesis gas production via lignin slurry gasification and high-temperature removal of hydrogen sulphide from the synthesis gas over calcium aluminate supported nickel ...oxide catalyst (NiO/CaAl2O4) was investigated. The goal of this study was to clarify the effects of the operating temperature (750–950 °C), moisture content of the lignin slurry (73–90 wt%), and catalyst loading (0.00–0.61 g-catalyst/g-feedstock) on the sulphur balance of the process and to determine the appropriate catalyst loading with cleaner biosyngas via utilisation of the sensible heat for smaller additional heat, which is maintained at the temperature of the gasifier. The biosyngas generated from gasification of lignin slurry, which contained hydrogen sulphide (H2S) and carbonyl sulphide (COS), was subjected to sulphur removal catalysed by NiO/CaAl2O4; a sulphur yield on NiO/CaAl2O4 of 0.14 mmol/g-lignin was achieved at the moisture content of 80.0 wt%, the reaction temperature of 900 °C, and the catalyst loading of 0.16 g-catalyst/g-feedstock. For the catalytic H2S removal system applicable to solid oxide fuel cells, the performance efficiency was introduced to discuss the optimal catalyst loading amount; the performance efficiency was 0.63–0.72 S-mol%·g-lignin/kJ for the catalytic operations while 0.33 S-mol%·g-lignin/kJ for non-catalytic operation.
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•Effects of operating gasifying conditions on the sulphur balances were clarified.•Subsequent sulphur removal over NiO/CaAl2O4 surface was also investigated.•The catalyst decreased 17.6 S-mol% of sulphur compared with that of non-catalytic.•The catalyst loading for high sulphur purity and low additional heat were proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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