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Parameter estimation for reactive chromatography model by Bayesian inference and parallel sequential Monte Carlo
No full texteactive chromatography overcomes many disadvantages of conventional separation processes by improving yields and reduces costs by combining reaction and separation in a single operation. Model-based optimization is essential to realize industrial applications of this process. Parameters in the model must be estimated accurately, and evaluating the uncertainty of the model parameters is crucial. However, uncertainty quantification of model parameters has not been performed for reactive chromatography processes. In this study, we propose an approach to estimate the parameter uncertainty of reactive chromatography processes using Bayesian inference and parallel sequential Monte Carlo. As an example, the esterification synthesis of acetic acid and methanol catalyzed by a cation exchange resin was considered. Parameter estimation was performed using a reactive chromatography experiment and a non-reactive experiment in which only the products were injected. The results of the analysis showed that using both the reactive and non-reactive chromatography experimental data simultaneously improved the accuracy of the estimation. In addition, correlations between some parameters were revealed
Small ship collisions in coastal areas during tsunamis: Impact on seawalls behind sand dunes
No full textCoastal regions often feature seawalls situated behind sand dunes, introducing unique topographical factors that significantly influence ship drift and collision behavior. This study investigates the collision dynamics of a small ship, particularly fishing boats, in coastal areas during tsunamis and the subsequent impact forces on a seawall behind dunes. Through hydraulic model experiments, the characteristics of tsunami-driven drift, collision probabilities, and instantaneous impact forces were examined. The likelihood of ship collisions with seawalls increased when the dimensionless initial position of a ship (the ratio of its distance from the shore to the tsunami breaking point) was less than 0.6. The impact force experienced by a ship was influenced by the behavior of the water mass rising in front of the seawall post-tsunami. Collisions before the descending water mass resulted in increased impact forces, while collisions post-descent showed forces decreased owing to reduced drift velocity. In cases where ships encountered falling water masses before a collision, impact forces decreased significantly compared to other scenarios. An equation to estimate ship impact velocity, accounting for dune effects, based on the dimensionless time difference between the tsunami and ship collision and the tsunami propagation velocity calculated from near-shore tsunami height was introduced. This equation considers the damping effect of impact velocity, improving accuracy within the experimental range of small impact forces
Removal of heavy metals by BEA zeolite/Fe3O4 composite prepared via dry-gel conversion method using agrowaste-derived raw material
No full textUsing agrochemicals are considered as an anthropogenic source of heavy metal contamination in water, and ecofriendly remediation tools for removal is desired. Here, we demonstrate material circulation by converting SiO2 extracted from agrowaste: rice husk ash, into an easily collectable adsorbent: BEA zeolite/Fe3O4 composite, through dry-gel conversion technique. In addition, the synthesized BEA zeolite/Fe3O4 composite was tested for removal of heavy metals for the first time. Instrumental analyses confirmed that incorporated Fe3O4 particles inside BEA zeolites showed no severe effects on its morphologies. Pseudo-second order kinetic and Langmuir isotherm models were found best described the adsorption of three typical toxic heavy metals: Pb(II), Cu(II), Zn(II). Moderate adsorption capacities of 0.675, 0.310, and 0.308 mmol/g for Pb(II), Cu(II), and Zn(II), respectively, following the selectivity order: Pb(II) > Cu(II) ≈ Zn(II) were obtained. The composite adsorbent exhibits magnetic collectability, reusability and stability, indicating its practicality for removal of heavy metals from water
Eulerian finite volume method using Lagrangian markers with reference map for incompressible fluid–structure interaction problems
No full textWe propose a monolithic fluid–structure interaction (FSI) method that presents the advantages of both the reference map technique (RMT) and the Lagrangian Markers approach on a unified, cell-centered finite volume Eulerian framework. Full Eulerian methods that use a Cartesian mesh are attractive for FSI problems that require large-scale computing and involve complex geometries and large solid deformations. However, conventional full Eulerian methods use the velocity gradient to evaluate solid deformations, hence they suffer from numerical instability caused by the discontinuity of the velocity gradient near the interface. In this work, we develop a novel algorithm that interpolates and transfers a reference mapping information field between a collection of Lagrangian Markers and a Eulerian finite volume framework. As a result of integrating these approaches, our method is able to (1) evaluate solid deformations without computing the velocity gradient in the Eulerian framework thanks to RMT, and (2) remove the numerical dissipation of interfaces and internal variables caused by advection in the full Eulerian RMT, thanks to the use of the Lagrangian Markers to compute the constitutive equations. We illustrate with numerical examples that the proposed method preserves geometrical features and yields more accurate results for the deformation and energy than conventional Eulerian FSI method and the full Eulerian RMT
Nano-captured water affects the wettability of cellulose nanofiber films
No full textIn this study, we report that the wettability of cellulose nanofiber films varies with their thickness, and this variation is attributed to the amount of water captured within the hydrogel-like film. To investigate this, we conducted water contact angle measurements on cellulose nanofiber films with different thicknesses. The wettability of the films was found to change from hydrophilic (approximately 20°) to that of the underlying silicon substrate (approximately 80°) by decreasing the mean film thickness within a range of 150 nm or less. Transmission electron microscope observations revealed that even under high-vacuum conditions ( Pa), water was captured in regions where the film was thick enough to form a dense, three-dimensional network. However, in regions where the film was thin, the network structure became sparse and two-dimensional, and no water was observed. We propose that the wettability of cellulose nanofiber films changes based on the area ratio of water captured in thick 3D network regions, the underlying substrate, and the cellulose nanofibers. Furthermore, we quantitatively evaluated the relationship between the area ratio and the wetting state of the composite surface based on the Cassie-Baxter equation, then determined the minimum thickness at which water is retained within the cellulose fiber network
化学療法後に経過観察期間を経て外科的切除を行った性腺外胚細胞腫瘍の1例
No full textThe patient was a 21-year-old man with a shadow on a chest roentgenogram taken during a medical checkup. According to blood testing, thoracoabdominal computed tomography, head magnetic resonance imaging, and lung tumor biopsy, we diagnosed a primary retroperitoneal germ cell tumor with multiple lung and brain metastases. Induction chemotherapy (4 courses of Bleomycin, Etoposide and Cisplatin) was started immediately. Because tumor markers remained elevated, salvage chemotherapy (4 courses of paclitaxel, ifosfamide cisplatin) was administered. Since the tumor markers remained elevated third-line chemotherapy was considered. However, because the tumor markers continued to decrease gradually and the tumor continued to shrink on imaging, expectant management was given. Three months later, the tumor markers turned negative, and retroperitoneal lymph node dissection and resection of lung metastases were performed. No cancer cells were found in any of the tissue samples. Careful monitoring after completion of chemotherapy may spare unnecessary chemotherapy.本論文の要旨は，第110回日本泌尿器科総会において発表した
Equal surplus sharing values for games with coalition structures
No full textWe provide axiomatic characterizations of three equal surplus sharing values—the CIS, ENSC, and ED values—within the class of games with coalition structures. Our approach employs the “splitting” axiom, introduced by Casajus (2009). We axiomatically compare these three values with the value concepts proposed by Aumann and Drèze (1974) and Casajus (2009)
Size of icy grains after a heating event in a protoplanetary disk
No full textA heating event in a protoplanetary disk could sublimate H2O ice from icy aggregates. After the heating event, the temperature decreased, and the H2O vapor recondensed to form pure H2O grains through homogeneous nucleation or to formH2O ice layer covering the silicate aggregates left behind during the heating event. As a result, the size of the pure H2O ice grains could change from the commonly assumed value of 0:1 m of the aggregate composing ice-covered grains. Here, we numerically determined the final radii of the grains and the thickness of the H2O ice layer on the aggregates after the cooling.We also estimated the maximum radius of the aggregate consisting of the processed grains. If the size of the silicate aggregate left behind in the heating event was smaller than 0:073 m, continuous collisional growth of the aggregates of the processed grains was possible. If the size was larger than 0:073 m, a short cooling time depending on the heliocentric distance was required to achieve high mechanical strengths of the aggregates for the collisional growth
