Nonpolymer Organic Solar Cells: Microscopic Phonon Control to Suppress Nonradiative Voltage Loss via Charge-Separated State.

Recent remarkable developments on nonfullerene solar cells have reached a photoelectric conversion efficiency (PCE) of 18% by tuning the band energy levels in small molecular acceptors. In this regard, understanding the impact of small donor molecules on nonpolymer solar cells is essential. Here, we systematically investigated mechanisms of solar cell performance using diketopyrrolopyrrole (DPP)-tetrabenzoporphyrin (BP) conjugates of C4-DPP-H2BP and C4-DPP-ZnBP, where C4 represents the butyl group substituted at the DPP unit as small p-type molecules, while an acceptor of [6,6]-phenyl-C61-buthylic acid methyl ester is employed. We clarified the microscopic origins of the photocarrier caused by phonon-assisted one-dimensional (1D) electron-hole dissociations at the donor-acceptor interface. Using a time-resolved electron paramagnetic resonance, we have characterized controlled charge-recombination by manipulating disorders in π-π donor stacking. This ensures carrier transport through stacking molecular conformations to suppress nonradiative voltage loss capturing specific interfacial radical pairs separated by 1.8 nm in bulk-heterojunction solar cells. We show that, while disordered lattice motions by the π-π stackings via zinc ligation are essential to enhance the entropy for charge dissociations at the interface, too much ordered crystallinity causes the backscattering phonon to reduce the open-circuit voltage by geminate charge-recombination.

Periodic sea-level oscillation in Tokyo Bay detected with the Tokyo-Bay seafloor hyper-kilometric submarine deep detector (TS-HKMSDD).

Meteorological-tsunami-like (or meteotsunami-like) periodic oscillation was muographically detected with the Tokyo-Bay Seafloor Hyper-Kilometric Submarine Deep Detector (TS-HKMSDD) deployed in the underwater highway called the Trans-Tokyo Bay Expressway or Tokyo Bay Aqua-Line (TBAL). It was detected right after the arrival of the 2021 Typhoon-16 that passed through the region 400 km south of the bay. The measured oscillation period and decay time were respectively 3 h and 10 h. These measurements were found to be consistent with previous tide gauge measurements. Meteotsunamis are known to take place in bays and lakes, and the temporal and spatial characteristics of meteotsunamis are similar to seismic tsunamis. However, their generation and propagation mechanisms are not well understood. The current result indicates that a combination of muography and trans-bay or trans-lake underwater tunnels will offer an additional tool to measure meteotsunamis at locations where tide gauges are unavailable.

Green analytical method for the simultaneous analysis of cytochrome P450 probe substrates by poly(N-isopropylacrylamide)-based temperature-responsive chromatography.

High-performance liquid chromatography (HPLC) is the most common analytical method practiced in various fields and used for analysis of almost all drug compounds in the pharmaceutical industries. During drug development, an evaluation of potential drug interaction with cytochrome P450 (CYP) is essential. A "cocktail" approach is often used in drug development to evaluate the effect of a drug candidate on multiple CYP enzymes in a single experiment. So far, simultaneous analysis of multiple CYP substrates, which have greatly different structure and physicochemical properties, has required organic solvents and mobile phase gradient methods. However, despite the recent emphasis on environmental protection, analytical methods that use only aqueous solvents without the use of organic solvents for separation have not been studied well. This study sought to develop the simultaneous analysis of multiple CYP substrates by using poly(N-isopropylacrylamide) (PNIPAAm)-based temperature-responsive chromatography with only aqueous solvents and isocratic methods. Good separation of multiple CYP substrates was achieved without using organic solvents and any gradient methods by temperature-responsive chromatography utilizing a P(NIPAAm-co-n-butyl methacrylate (BMA))- and P(NIPAAm-co-N-acryloyl L-tryptophan methyl ester (L-Trp-OMe))-grafted silica column. Overall, PNIPAAm-based temperature-responsive chromatography represents a remarkably simple, versatile, and environmentally friendly bioanalytical method for CYP substrates and their metabolites.

[Effect of Methylcellulose (Cellulose Derivatives) on Ibuprofen-crushing Efficiency in Nano Pulverizer NP-100].

It is expected that drug systems using nanoparticles will improve the problem of poor water solubility and bioavailability of lipophilic drugs. However, it is difficult to prepare the formulations containing nanoparticles, and it is important to determine the concentration and kind of additives to prepare the formulations. We previously reported that a nano pulverizer NP-100 is possible to prepare drug nanoparticles for the 2-3 min, and the cellulose derivatives (metolose®, methylcellulose) is usefulness to prepare the nanoparticles by the mill method. In this study, we investigated the relationships of methylcellulose type and crushing efficiency in NP-100. First, we demonstrated the effect of viscosity in the various methylcellulose on the ibuprofen (IBU, lipophilic drug) particle size, and showed that the viscosity did not relate the crushing efficiency by the NP-100. Next, we measured the changes of cumulative size frequency curve in IBU particles by the combination of the NP-100 and 0.1-2.0% methylcellulose (SM-4, 400 and 4000). The appropriate addition reached IBU nanoparticles, although, the appropriate addition amount of methylcellulose was different in the SM-4 (0.5%), 400 (1.0%) and 4000 (1.2%). In addition, the IBU became meringue-like when subjected to the bead mill method in the less of methylcellulose, and excessive addition of methylcellulose increased the ratio of coarse particle. In conclusion, this results show that the appropriate addition amount of methylcellulose is different in the type of methylcellulose, and these changes of cumulative size frequency curve is useful as index to determine the concentration and type of additives in the nanoparticle production.

Wavelet-based regularization of the Galerkin truncated three-dimensional incompressible Euler flows.

We present numerical simulations of the three-dimensional Galerkin truncated incompressible Euler equations that we integrate in time while regularizing the solution by applying a wavelet-based denoising. For this, at each time step, the vorticity field is decomposed into wavelet coefficients, which are split into strong and weak coefficients, before reconstructing them in physical space to obtain the corresponding coherent and incoherent vorticities. Both components are multiscale and orthogonal to each other. Then, by using the Biot-Savart kernel, one obtains the coherent and incoherent velocities. Advancing the coherent flow in time, while filtering out the noiselike incoherent flow, models turbulent dissipation and corresponds to an adaptive regularization. To track the flow evolution in both space and scale, a safety zone is added in wavelet coefficient space to the coherent wavelet coefficients. It is shown that the coherent flow indeed exhibits an intermittent nonlinear dynamics and a k^{-5/3} energy spectrum, where k is the wave number, characteristic of three-dimensional homogeneous isotropic turbulence. Finally, we compare the dynamical and statistical properties of Euler flows subjected to four kinds of regularizations: dissipative (Navier-Stokes), hyperdissipative (iterated Laplacian), dispersive (Euler-Voigt), and wavelet-based regularizations.

Small-scale anisotropic intermittency in magnetohydrodynamic turbulence at low magnetic Reynolds numbers.

Small-scale anisotropic intermittency is examined in three-dimensional incompressible magnetohydrodynamic turbulence subjected to a uniformly imposed magnetic field. Orthonormal wavelet analyses are applied to direct numerical simulation data at moderate Reynolds number and for different interaction parameters. The magnetic Reynolds number is sufficiently low such that the quasistatic approximation can be applied. Scale-dependent statistical measures are introduced to quantify anisotropy in terms of the flow components, either parallel or perpendicular to the imposed magnetic field, and in terms of the different directions. Moreover, the flow intermittency is shown to increase with increasing values of the interaction parameter, which is reflected in strongly growing flatness values when the scale decreases. The scale-dependent anisotropy of energy is found to be independent of scale for all considered values of the interaction parameter. The strength of the imposed magnetic field does amplify the anisotropy of the flow.

Intermittency and scale-dependent statistics in fully developed turbulence.

Fully developed homogeneous isotropic turbulent fields, computed by direct numerical simulation, are compared to divergence-free random fields having the same energy spectrum and either the same helicity spectrum as that of the turbulent data, or vanishing helicity. We show that the scale-dependent velocity flatness quantifies the spatial variability of the energy spectrum. The flatness exhibits a substantial increase at small scales for the turbulent field, but remains constant for the random fields. A diagnostic, the scale-dependent helicity, is proposed to quantify the geometrical statistics of the flow, which shows that only the turbulent flow is intermittent. Finally, statistical scale-dependent analyses of both Eulerian and Lagrangian accelerations confirm the inherently different dynamics of turbulent and random flows.