Long term observation of Magnetospirillum gryphiswaldense in a microfluidic channel

We controlled and observed individual magnetotactic bacteria (Magnetospirillum gryphiswaldense) inside a 5 {\mu}m high microfluidic channel for over four hours. After a period of constant velocity, the duration of which varied between bacteria, all observed bacteria showed a gradual decrease in their velocity of about 25 nm/s$^2$. After coming to a full stop, different behaviour was observed, ranging from rotation around the centre of mass synchronous with the direction of the external magnetic field, to being completely immobile. Our results suggest that the influence of the high intensity illumination and the presence of the channel walls are important parameters to consider when performing observations of such long duration.Comment: 7 pages, 11 figure

The Effects of Operational Efficiency and Environmental Risk on the Adoption of Environmental Management Practices

Given that prior research has provided inconsistent findings on the relationship between financial performance and the adoption of environmental management practices (EMPs), we aim to resolve the inconsistency by positing that the firm may consider different components of financial performance when making decisions. Specifically, we maintain that operational efficiency, measured based on net profit margin, is a key determinant of a firm’s decision to adopt EMPs. Additionally, we aim to examine environmental risk as one contingency that moderates the relationship between operational efficiency and EMP adoption. Employing a firm-fixed effect model to examine the effects of various measures of financial performance, including the net profit margin, return on asset (ROA), return on equity (ROE), and asset turnover, on the adoption rates of EMPs by firms, we find that firms with higher operational efficiency measured based on net profit margin are more inclined to adopt EMPs, while measures such as ROA, ROE, and asset turnover do not demonstrate any substantial effect. This study also finds that while environmental risk increases the possibility of adopting EMPs, it weakens the impact of operational efficiency on the adoption rates of EMPs

Ferroelectric Transition in Sr- and W-Doped BaTiO3 Solid Solutions

We synthesized Sr- and W-doped BaTiO3 (BTO) polycrystals by using a solid-state reaction method. The X-ray diffraction results showed that Sr and W atoms occupied the Ba and Ti sites in tetragonal BTO, respectively, and there were changes in the lattice constants and the volumes in the Sr- and W-doped BTO. We found a change in the latent heat and the Curie temperature (TC) during the transition between the ferroelectric and paraelectric phases while increasing the contents of Sr and W in the Sr- and W-doped BTO. This can be explained by the fact that the doping of Sr and W atoms in BTO prevented a distinct transition between the ferroelectric tetragonal and paraelectric cubic structures by decreasing the c/a ratio to a value close to unity. This study shows a way toward a strategy for modulating a crystal structure by using proper dopants for future applications in ferroelectricity-based devices

Reconfiguring Sodium Intercalation Process of TiS2 Electrode for Sodium-Ion Batteries by a Partial Solvent Cointercalation

Titanium disulfide (TiS2), a first-generation cathode in lithium batteries, has also attracted a broad interest as a sodium-ion battery electrode due to fast sodium intercalation kinetics and large theoretical capacity. However, the reversibility of sodium de/ intercalation is far inferior to that of lithium because of the unfavorable intermediate phase formation. Herein, we demonstrate that reconfiguring sodium intercalation via partial solvent cointercalation alters the phasetransition paths for the entire reactions of NaxTiS2 (0 < x < 1), detouring the formation of the unfavorable intermediates. Additionally, it unexpectedly results in a remarkable enhancement of sodium intercalation reversibility, boosting the cycle stability (1000 cycles) accompanying high power capability (10C rate). Comparative investigations reveal that the sodium intercalation in ether-based electrolyte involves a preintercalation of solvent molecules, which is subsequently dissimilar to the bare sodium intercalation in conventional electrolytes. Rediscovery of the intercalation behavior of TiS2 offers a new insight in revisiting the reversibility and kinetics of the commonly known electrodes for batteries.11Nsciescopu

Creating and Optimizing Interfaces for Electric-Field and Photon-Induced Charge Transfer

We create and optimize a structurally well-defined electron donor–acceptor planar heterojunction interface in which electric-field and/or photon-induced charge transfer occurs. Electric-field-induced charge transfer in the dark and exciton dissociation at a pentacene/PCBM interface were probed by <i>in situ</i> thickness-dependent threshold voltage shift measurements in field-effect transistor devices during the formation of the interface. Electric-field-induced charge transfer at the interface in the dark is correlated with development of the pentacene accumulation layer close to PCBM, that is, including interface area, and dielectric relaxation time in PCBM. Further, we demonstrate an <i>in situ</i> test structure that allows probing of both exciton diffusion length and charge transport properties, crucial for optimizing optoelectronic devices. Competition between the optical absorption length and the exciton diffusion length in pentacene governs exciton dissociation at the interface. Charge transfer mechanisms in the dark and under illumination are detailed

Thermoresponse of Odd-Even Effect in Self-Assembled Monolayers

This paper examines thermoresponse of odd-even effect in self-assembled monolayers (SAMs) of n-alkanethiolates (SCn, n = 3 – 18) formed on template-stripped gold (AuTS) using macro- and microscopic analytical techniques, contact angle goniometry (CAG) and vibrational sum frequency generation (VSFG) spectroscopy, respectively. Both CAG and VSFG analyses showed that the odd-even effect in liquid-like SAMs (n = 3 – 9) disappeared upon heating at 50 – 70 °C, indicating that the heating led to increased structural disorder regardless of odd and even carbon numbers. In contrast, the opposite thermoresponse was observed for odd and even SCn molecules in wax- and solid-like SAMs (n = 10 – 18). Namely, temperature-dependent orientational change of terminal CH3 relative to the surface normal was opposite for the odd and even molecules, thereby leading to mitigated odd-even effect. Our work offers important insights into thermoresponse of supramolecular structure in condensed organic matter

Thermoresponse of Odd-Even Effect in n-Alkanethiolate Self-Assembled Monolayers on Gold Substrates

This study examines thermoresponse of odd-even effect in self-assembled monolayers (SAMs) of n-alkanethiolates (SCn, n=3-18) formed on template-stripped gold (Au-TS) using macro- and microscopic analytical techniques, contact angle goniometry (CAG) and vibrational sum frequency generation (VSFG) spectroscopy, respectively. Both CAG and VSFG analyses showed that the odd-even effect in liquid-like SAMs (n=3-9) disappeared upon heating at 50-70 degrees C, indicating that the heating led to increased structural disorder regardless of odd and even carbon numbers. In contrast, the opposite thermoresponse was observed for odd and even SCn molecules in wax- and solid-like SAMs (n=10-18). Namely, temperature-dependent orientational change of terminal CH3 relative to the surface normal was opposite for the odd and even molecules, thereby leading to mitigated odd-even effect. Our work offers important insights into thermoresponse of supramolecular structure in condensed organic matter.11Nsciescopu

High Magnetic Field Sensitivity in Ferromagnetic–Ferroelectric Composite with High Mechanical Quality Factor

In this study, composite devices were fabricated using ferromagnetic FeSiB-based alloys (Metglas) and ferroelectric ceramics, and their magnetic field sensitivity was evaluated. Sintered 0.95Pb(Zr0.52Ti0.48)O3-0.05Pb(Mn1/3Sb2/3)O3 (PZT-PMS) ceramic exhibited a very dense microstructure with a large piezoelectric voltage coefficient (g31 = &minus;16.8 &times; 10&minus;3 VmN&minus;1) and mechanical quality factor (Qm &gt; 1600). Owing to these excellent electromechanical properties of the PZT-PMS, the laminate composite with a Metglas/PZT-PMS/Metglas sandwich structure exhibited large magnetoelectric voltage coefficients (&alpha;ME) in both off-resonance and resonance modes. When the length-to-width aspect ratio (l/w) of the composite was controlled, &alpha;ME slightly varied in the off-resonance mode, resulting in similar sensitivity values ranging from 129.9 to 146.81 VT&minus;1. Whereas in the resonance mode, the composite with small l/w exhibited a large reduction of &alpha;ME and sensitivity values. When controlling the thickness of the PZT-PMS (t), the &alpha;ME of the composite showed the largest value when t was the smallest in the off-resonance mode, while &alpha;ME was the largest when t is the largest in the resonance mode. The control of t slightly affected the sensitivity in the off-resonance mode, however, higher sensitivity was obtained as t increased in the resonance mode. The results demonstrate that the sensitivity, varying with the dimensional control of the composite, is related to the mechanical loss of the sensor. The composite sensor with the PZT-PMS layer exhibited excellent magnetic field sensitivity of 1.49 &times; 105 VT&minus;1 with a sub-nT sensing limit, indicating its potential for application in high-performance magnetoelectric sensor devices

Abnormally High-Lithium Storage in Pure Crystalline C-60 Nanoparticles

Li+ intercalates into a pure face-centered-cubic (fcc) C-60 structure instead of being adsorbed on a single C-60 molecule. This hinders the excess storage of Li ions in Li-ion batteries, thereby limiting their applications. However, the associated electrochemical processes and mechanisms have not been investigated owing to the low electrochemical reactivity and poor crystallinity of the C-60 powder. Herein, a facile method for synthesizing pure fcc C-60 nanoparticles with uniform morphology and superior electrochemical performance in both half- and full-cells is demonstrated using a 1 m LiPF6 solution in ethylene carbonate/diethyl carbonate (1:1 vol%) with 10% fluoroethylene carbonate. The specific capacity of the C-60 nanoparticles during the second discharge reaches approximate to 750 mAh g(-1) at 0.1 A g(-1), approximately twice that of graphite. Moreover, by applying in situ X-ray diffraction, high-resolution transmission electron microscopy, and first-principles calculations, an abnormally high Li storage in a crystalline C-60 structure is proposed based on the vacant sites among the C-60 molecules, Li clusters at different sites, and structural changes during the discharge/charge process. The fcc of C-60 transforms tetragonal via orthorhombic LixC60 and back to the cubic phase during discharge. The presented results will facilitate the development of novel fullerene-based anode materials for Li-ion batteries

Long term observation of Magnetospirillum gryphiswaldense in a microfluidic channel

We controlled and observed individual magnetotactic bacteria (Magnetospirillum gryphiswaldense) inside a 5 {\mu}m high microfluidic channel for over four hours. After a period of constant velocity, the duration of which varied between bacteria, all observed bacteria showed a gradual decrease in their velocity of about 25 nm/s$^2$. After coming to a full stop, different behaviour was observed, ranging from rotation around the centre of mass synchronous with the direction of the external magnetic field, to being completely immobile. Our results suggest that the influence of the high intensity illumination and the presence of the channel walls are important parameters to consider when performing observations of such long duration