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This article reports on the long-term variation of the spectral smile and the full-width at half-maximum (FWHM) of the sensor response function for the Hyperspectral Imager Suite (HISUI) onboard the International Space Station (ISS). HISUI is an optical hyperspectral imager comprising two subsystems: a visible-and-near-infrared (VNIR) system covering 400–980 nm and a short-wave infrared (SWIR) system covering 895–2481 nm. On the basis of atmospheric corrections for actual observation images, we found that the characteristics of the spectral smile and the FWHM can be classified into five major periods. The results show that the first two transitions of the periods are due to updates of the smile correction table used in HISUI and that the last one is related to the occurrence of vertical stripes in the HISUI images. However, two unexpected changes are observed. One is a sudden increase in the spectral smile in the SWIR data to 2.0–2.1 nm on September 30, 2021, which was just three days after the second update of the smile correction table. The other is a sudden improvement on January 5, 2022, showing almost zero spectral smile and a nearly constant FWHM. Because neither sudden change is associated with HISUI or ISS operations/events, the optical and electrical systems of HISUI might exhibit instability, leading to sporadic changes of the spectral smile and FWHM. The findings of this study therefore suggest that, although the postlaunch spectral smile correction has been completed, continued long-term evaluation of the spectral stability is important.

Synchrotron radiation X-ray computed tomography (CT) provides information about the three-dimensional electron density inside a sample with a high spatial resolution. Recently, the need to examine the internal structure of materials composed of light elements, such as water and carbon fibers in resins, has increased. Small density differences in these systems give low X-ray contrast; segmentation methods suited for this type of problem are necessary. Machine learning is typically used to analyze CT data, and a large amount of training data is required to train a machine learning model. Conversely, transfer learning, which uses existing learning models, can develop a learning model using only a small amount of training data. In this study, the synchrotron radiation X-ray CT images of an epoxy resin containing water have been analyzed using transfer learning as the validation of a method for analyzing low-contrast CT data with high accuracy. Circular domain structures in the resin have been observed using the X-ray CT method, and statistical information about these structures has been successfully obtained by transfer learning-based analysis. Here, transfer learning is performed using twelve slices within an X-ray CT 3D image, demonstrating that low-contrast synchrotron CT data can be segmented with a small amount of training data.

Thermal remote sensing is an important tool for monitoring regional climate and environment, including urban heat islands. However, it suffers from a relatively lower spatial resolution compared to optical remote sensing. To improve the spatial resolution, various "data-driven" image processing techniques (pan-sharpening, kernel-driven methods, and machine learning) have been developed in the previous decades. Such empirical super-resolution methods create visually appealing thermal images; however, they may sacrifice radiometric consistency because they are not necessarily sensitive to specific sensor features. In this paper, we evaluated a "sensor-driven" super-resolution approach that explicitly considers the sensor blurring process, to ensure radiometric consistency with the original thermal image during high-resolution thermal image retrieval. The sensor-driven algorithm was applied to a cloud-free Moderate Resolution Imaging Spectroradiometer (MODIS) scene of heterogeneous urban and suburban landscape that included built-up areas, low mountains with a forest, a lake, croplands, and river channels. Validation against the reference high-resolution thermal image obtained by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) shows that the sensor-driven algorithm can downscale the MODIS image to 250-m resolution, while maintaining a high statistical consistency with the original MODIS and ASTER images. Part of our algorithm, such as radiometric offset correction based on the Mahalanobis distance, may be integrated with other existing approaches in the future.

The purpose of this study is to simulate unsteady steam flows through three-stage stator and rotor blade passages in a middle-pressure steam turbine operated in a power plant while considering manufactured and secular-changed blade shapes. The shapes of the manufactured and secular-changed blades are measured during overhaul. The numerical method is based on an in-house code developed by Tohoku University. The time-dependent pressure and the Mach number are visualized, and the difference of the results obtained by assuming manufactured and secular-changed blades is explained. The simulated static temperatures assuming the blades shapes are then compared with each other and with the measured data. In addition, a simple method modifying the simulated static temperature considering real gas effect is introduced.

Summary:. Reconstruction of a defect in the labial area has to be performed by taking account of the shape of the labial area and urogenital function. The gracilis myocutaneous flap and the gluteal fold flap are commonly used reconstructive procedures, but sometimes these flaps are too bulky and cause a deviation of the urination stream and/or deformity of the reconstructed site. In this report, we present our unique method of reconstruction using a contralateral labia majora sharing perforator flap. The patient was a 76-year-old woman who presented with squamous cell carcinoma on the left labia majora. Following radical vulvectomy with 2 cm radial margins and left inguinofemoral lymphadenectomy, an 8 × 6 cm2 defect was created. Primary closure was possible, but there was a risk that it might cause an unfavorable deformity and exposure of the urethral and vaginal vestibule. Part of the contralateral side of the labia was used for a dorsal clitoral artery perforator–based transposition sharing flap. The defect was covered without tension, and the donor site was closed primarily. The postoperative course was good. One year after the operation, deviation of the urination stream and severe asymmetry was not observed. This study shows feasibility of perforator-based labia majora sharing flap for contralateral labia majora defect. Our “like with like” reconstruction provides a good functional outcome and less donor-site morbidity to the patient.

Summary:. A phyllodes tumor of the breast is a rare neoplasm, accounting for 0.3%–1% of all breast cancers. The size is 4–5 cm on average but sometimes the tumor grows more and involves the entire breast. As for treatment, complete surgical resection is the standard for localized breast phyllodes tumors. The reconstruction of a large defect is challenging. Herein, we present a case where a deep inferior epigastric artery perforator (DIEP) flap was used in breast reconstruction for a 48-year-old woman who was suffering from a giant phyllodes tumor. Immediate reconstruction was performed after tumor excision; the specimen weighed 4,230 g and the skin defect was 22 × 24 cm. The deep inferior epigastric artery and vein were anastomosed to the right internal mammary artery and vein, and the superficial inferior epigastric vein was anastomosed to the right lateral thoracic vein. The postoperative course was uneventful and the DIEP flap survived completely. In the setting of the reconstruction for a large defect, we must make maximum use of the limited human tissue available and ensure minimum damage, while also considering the functional and aesthetic outcome of the donor site. Various ideas and technologies have been reported that can assist in achieving this goal, but few reports have commented especially on the reconstruction of giant phyllodes tumor using autologous tissues. There were some other options for the way of the reconstruction such as a latissimus dorsi flap and a rectus abdominis flap. Compared with these approaches, using a DIEP flap has some disadvantages such as the need for the microsurgical skill and the risk of postoperative hernia. However, a DIEP flap provides the enough tissue to cover the large defect without any damage of the muscle. To our knowledge, this case was the largest phyllodes tumor reconstruction ever, in terms of the amount of the skin needed and resected tissue involved. Although more studies and longer follow-up will be required in the future, this case may show the usefulness of DIEP flaps for reconstruction of a giant phyllodes tumor.

Recently, the growing number of hyperspectral satellite sensors have increased the demand for a flexible and robust approach to their calibration. This paper proposes an operational method for the simultaneous correction of inter-sensor and inter-band biases in hyperspectral sensors via the soil line concept for spectral band adjustment. Earth Observing-1 Hyperion was selected as an example, with the Terra Moderate Resolution Imaging Spectroradiometer (MODIS) as a reference. The results over the Railroad Valley Playa calibration site indicated that the discrepancy in the analogous bands between Hyperion and MODIS during 2001–2008 was approximately 4–6% and 7–9% of the root-mean-square error in the top-of-atmosphere (TOA) radiance at the visible and near-infrared region and shortwave infrared region, respectively. For all Hyperion bands, the relative cross-calibration coefficients during this period were calculated (typically ranging from 0.9 to 1.1) to correct the Hyperion TOA radiance to be consistent with the MODIS and the other Hyperion bands. The application of the proposed approach could allow for more flexible cross-calibration of irregular-orbit sensors aboard the International Space Station.

The causal relationship between unsteady forces of wet-steam flows on rotor-blade rows and the steam condensation in low pressure steam turbines is still one of unresolved issues. In this study, we investigate the effect of condensation on the time-dependent torque of final-stage long-rotor blade rows in a low pressure steam turbine. Then we simulate unsteady wet-steam flows through the three-stage stator-rotor blade rows in the steam turbine while changing the inlet temperature condition. The variation of the inlet temperature results in creating a flow field with a different amount of wetness due to condensation. The temperature and pressure in the flow field obtained from a different inlet temperature are compared with each other, and the torques calculated from the time-dependent pressure on a final-stage long-rotor blade are also relatively compared. The calculated results in this study indicate that the time-dependent torques on the final-stage long-rotor blade significantly depend on the latent heat added by condensation and that the amount of condensation is highly sensitive to variations in the inlet temperature. This study also suggests that an optimal inlet temperature may be exist for optimizing the torque of low pressure steam turbines.

Wet-steam flows under high-pressure conditions are numerically investigated using a newly derived condensation model that assumes a real gas and uses a real gas Equation of State (EOS). Under high-pressure conditions, the present condensation model calculates the critical radius of a water droplet that is larger than that of the conventional model. The results indicate that nucleation is initiated farther downstream in the nozzle and the nucleation rate is smaller. Wet-steam nozzle flows under high-pressure conditions are simulated and the results are compared with experimental results. The present model simulates the pressure increase due to the release of latent heat of condensation more accurately than the conventional method based on the ideal gas assumption. The results obtained are also in good agreement with the experimental results.

To reduce aerodynamic drag, reduction of skin friction is required. Vibrant flexible wall has been proposed to reduce skin friction drag for a long time. However, there are many problems for the flexible wall to get practical durability, easy maintenance and reasonable cost. On the other hand, vibrant solid wall, which is much adequate for a car body, has been rarely proposed. In this research, mechanism of drag reduction by a vibrating solid wall is considered from the velocity distribution near the wall surface. Reduction of skin friction drag on a vibrant wall is mainly caused by decrease of Reynolds shear stress, and the effect of shear stress from velocity gradient near the wall is small. The optimum condition of vibration for drag reduction is also discussed in this paper.

Building Cube Method (BCM) adopts block-structured Cartesian mesh and finer resolution can be used where the flow contains detailed flow structures. This paper reports the recent progress in extending BCM to curvilinear body-fitted mesh with Adaptive Mesh Refinement (AMR). Compared to Cartesian mesh based AMR, body-fitted AMR strategy is more complicated and less studied. In this paper the key components of body-fitted curvilinear mesh based AMR are introduced. A pressure based refinement criterion is used to detect both shock wave and strong vortex. Cubic interpolation is used to preserve the quality of the refined mesh. A sub-block based refinement strategy is also developed for the treatment of singular geometry features. Combined with the high order scheme, an accurate and robust curvilinear mesh based AMR tool is developed with which the flow details can be automatically captured. Numerical examples are given to validate the numerical properties of current AMR tool and to demonstrate the benefits of current body-fitted AMR strategy.

In this study, numerical simulations of supercritical-water flows over an arbitrary geometry are presented. In the present method, the supercritical-fluids simulator (SFS) developed by the authors is coupled with the building-cube method (BCM). Further, an immersed boundary (IB) method is applied to the wall boundary treatment, and the mathematical models for water programmed in PROPATH are used for thermophysical property estimation. First, as a classical case, steady laminar flows over a circular cylinder are simulated for numerical validation because of the simplicity of the model. Next, as another classical case, unsteady laminar flows past two side by side circular cylinders are computed with more complex physics of flow interactions. Finally, an E-shaped fin geometry is employed as an arbitrary geometry model in practical applications, and natural and forced convection flows over the E-shaped fin are investigated using the present method. The obtained results indicate that the aerodynamic characteristics of supercritical water are identical to that of conventional fluid based on the same Reynolds number, whereas the heat transfer effects are significantly different based on the distinctive Prandtl numbers. In addition, it is revealed that in the practical applications of supercritical-water flows, the intensity of the natural convection flow tends to be much stronger than that in liquid and gas state water flows at the same scale of geometry. The present method is demonstrated to be a promising tool for two-dimensional practical supercritical-fluid flow simulations with arbitrary geometry and complex physics.