bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time cells in the human hippocampus and entorhinal cortex support episodic memory
Authors: Umbach Gray , Kantak Pranish , Jacobs Joshua , Kahana Michael , Pfeiffer Brad E. , Sperling Michael , Lega Bradley 
Published: October 2020

Significance
Time cells are neurons in the hippocampus and entorhinal cortex that fire at specific moments within a cognitive task or experience. While many prominent theories of memory encoding offer time cells as the source of the temporal component to memory, they have never been observed in human recordings. We identify time cell populations in the medial temporal lobe of humans during memory encoding and retrieval. Further, we demonstrate that the stability of the time signal provided by time cells during encoding influences the ability to temporally order memories at time of retrieval.
Effective resistances of two-dimensional resistor networks
Authors: Mishra Rajat Chandra , Barman Himadri 
Published: October 2020

Abstract
We investigate the behavior of two-dimensional resistor networks, with finite sizes and different kinds (rectangular, hexagonal, and triangular) of lattice geometry. We construct a network by having a network unit repeat itself L

x
times in the x-direction and L

y
times in the y-direction. We study the relationship between the effective resistance (R
eff) of the network on dimensions L

x
and L

y
. The behavior is simple and intuitive for a network with rectangular geometry; however, it becomes non-trivial for other geometries which are solved numerically. We find that R
eff depends on the ratio L

x
/L

y
in all three studied networks. We also check the consistency of our numerical results experimentally for small network sizes.
Electrochemical detection of baicalein based on a three-dimensional micromixer
Authors: Liang Jie , Yu Jianfeng , Cheng Yang , Wu Yang , Li Yongliang 
Published: October 2020

Abstract
Baicalein, a kind of flavonoid, has many medical benefits, and therefore, its accurate and efficient determination is necessary in the field of medical ingredient detection. To achieve the rapid and precise detection of baicalein, a three-dimensional (3D) expansion–contraction wave micromixer was designed and used along with an electrochemical detection method to assemble a micromixing electrochemical detection system. First, the performances of the wave micromixers were investigated using the COMSOL Multiphysics 5.3 a software with three optimisation objectives, namely, the mixing uniformity, pressure drop, and mixing performance index, to comprehensively evaluate the properties of the micromixers. Second, a 3D expansion–contraction wave micromixer with optimal mixing properties was fabricated using the 3D printing technology. Third, a micromixing electrochemical detection system was built to study the redox behaviours of baicalein through the electrochemical cyclic voltammetry method. The effects of buffer varieties, buffer pH values, scanning speeds, and inlet flow rates on the redox curves of baicalein were studied to determine the appropriate experimental conditions. The results demonstrated that the currents of the oxidation peak increased linearly with the baicalein concentrations within the range of 3.55 × 10−6–5.92 × 10−5 mol l−1 and the detection limit of 1.861 × 10−8 mol l−1 (S/N = 3). The relative standard deviation among the results obtained through repeated experiments was 2.86%; this proves a high detection reproducibility of the new method. Compared with spectrophotometry, the error determined using the novel method in a real sample detection was 0.31%, thus achieving an efficient and precise detection of baicalein. The micromixing electrochemical detection method can remarkably improve the mixing efficiency, shorten the detection time, and decrease the detection limit, and therefore could be popularised for the exact content detection of other flavonoids.
Development of mechanically-robust piezoelectric micromachined ultrasonic transducer based on island-shaped monocrystalline PZT thin film partially covered with polyimide
Authors: Thao Pham Ngoc , Yoshida Shinya , Tanaka Shuji 
Published: October 2020

Abstract
This paper describes a new design of piezoelectric micromachined ultrasonic transducer (pMUT) with a monocrystalline Pb(Zr,Ti)O3-based thin film (Mono-PZT) for enhancing the mechanical robustness. In this study, we investigated two design concepts to suppress crack generation in Mono-PZT. First, the area of Mono-PZT is limited by leaving an island Mono-PZT pattern only on the membrane of the pMUT. Second, the edge of Mono-PZT is covered with a polyimide (PI) thin film as a protection layer to prevent the peeling. We prepared three different designs, a new design with both concepts, another design with the first concept, and the conventional one with neither of them for comparison. The robust mechanical analyses of these devices were performed by driving resonantly and increasing the displacement of the membranes. As these results, the proposed structure with both concepts still stands well at the highest displacement, 1600 nm, while the undesired cracks occur on other structures with approximately 800 nm of displacement. The robustness could improve 50% in comparison to the other designs thanks to this unique design. Finite element method simulation results showed that this PI layer contributed to decrease the stress concentrated at the edge both in the static condition and in the dyanamic vibarion of the membrane. This layer also probably played a role in prevention of the peeling of the edge of the island-shaped Mono-PZT. In conclusion, the new design is useful for the Mono-PZT pMUT in terms of excellent mechanical robustness.
Transport and calorimetry study of 20% La-doped CeIn3
Authors: Kim Suyoung , Seo Soonbeom , Gu Dachun , Kim Sung-II , Kim In-Cheol , Park Chan-Koo , Lee Hanoh , Park Tuson 
Published: October 2020

Abstract
CeIn3, a prototypical antiferromagnet, is an ideal candidate for investigating the relationship between magnetism and superconductivity, as superconductivity is induced as the magnetic transition temperature (T
N) is lowered to 0 K by applying pressure. When La is substituted for Ce, T
N of CeIn3 decreases to 0 K owing to the Ce dilution effects, thereby providing an alternative route to the zero-temperature quantum phase transition. In this study, we report a combinatorial approach to gain access to the critical point by applying external pressure to 20% La-doped CeIn3. Electrical resistivity measurements of La0.2Ce0.8In3 show that the T
N of 8.4 K at 1 bar is gradually suppressed under pressure and can be extrapolated to 0 K at approximately 2.47 GPa, thereby showing a similar pressure dependence of T
N as shown by undoped CeIn3. The kink-like feature in resistivity at T
N of CeIn3 changed to an obvious jump in the doped compound for pressures higher than 1.64 GPa, indicating depletion in the carrier density due to a gap opening. AC calorimetry measurements under applied pressure show that the size of the specific heat jump at T
N decreases with increasing pressure, but any signatures associated with the gap opening are not obvious, suggesting that the pressure-induced kink-to-jump change at T
N in the resistivity is not a phase transition, but rather a gradual crossover. The low-temperature specific heat divided by temperature, C/T, does not strongly diverge with decreasing temperature, but is almost saturated near the projected quantum critical point, which can be attributed to a weak enhancement in the effective mass up to 2.6 GPa.
Strain-driven dynamic stability and anomalous enhancement of thermal conductivity in graphene-like IIA–VI monolayer monoxides
Authors: Xia Chongqun , Zhao Yunshan , Ma Dengke , Li Xiuling , Zhang Lifa 
Published: October 2020

Abstract
Graphene-like IIA–VI monolayer monoxides have been predicted to be novel two-dimensional materials with intrinsic bandgap, which makes them promising prospect for electronics and optoelectronics applications. In the field of microelectronics, heat dissipation is considered as the bottleneck that limits further development. Thus, the effective regulation in thermal transport is of great interest for designing novel devices. A systematic study in this work is carried out by first-principles method to explore thermal conductivity of these monoxides under strain. Compared with that of minimum strained MgO, CaO, SrO and BaO, the maximum thermal conductivity is increased by 3.25, 3.07, 1.50 and 1.53 times, respectively, under tensile strain. Detailed analysis shows that the weakened phonon–phonon scattering strength is the behind physical mechanism. It is also found that the tensile strain aids to improving the stability. Our work provides an attractive platform by studying the thermal transport of these monoxides under strain, suggesting the possible applications of these monolayers in novel devices.
A review of radiation doses and associated parameters in Western Australian mining operations that process ores containing naturally occurring radionuclides for 2018–19
Authors: Ralph Martin I , Chaplyn Andrew , Cattani Marcus 
Published: October 2020

Abstract
Naturally occurring radionuclides (NORs) are encountered in varying concentrations in a wide range of commodities that are mined and processed in Western Australia (WA), including mineral sands, coal, phosphate ores, sandblasting materials, and the production of bauxite, titanium dioxide pigment, copper, zinc, lead, tin, tantalum and the refining of zircon.
Because they have the potential for workers to receive annual doses in excess of 1 mSv, 14 mining operations in WA are required to submit an annual report of worker doses to the regulatory authority. This research provides a summary of the workforce demographics and radiation doses reported by mining operations for the 2018–19 reporting period in order to establish a benchmark against which to compare future worker exposures. The 2018–19 data is compared to that presented in the last peer-reviewed research, published in 1994 in order to evaluate changes in worker dose profiles over the intervening period.
In 1992–93, the collective effective dose received by 1496 workers across seven mining operations was 2824 man.mSv, whereas in 2018–19 it had decreased to 784 man.mSv for 1474 workers in 13 operations. The maximum committed effective dose (CED) decreased by 76%, from 18 mSv (36% of the annual limit) in 1992–93 to 4.4 mSv (22% of the derived annual limit) in 2018–19. The mean CED decreased by 49%, from 1.8 mSv in 1992–93 to 0.97 mSv in 2018–19.
As a result of revised DC’s published in ICRP-137 and ICRP-141, the impacts upon the mean CED per unit intake of alpha activity arising from inhalation of insoluble NORs-containing dusts, and contribution to CED from inhalation of radon, thoron and their progeny will require evaluation for individual mining operations in the WA mining industry.
The compatibility of methylammonium and formamidinium in mixed cation perovskite: the optoelectronic and stability properties
Authors: Guo Xinlu , Ngai Kwanho , Qin Minchao , Lu Xinhu , Xu Jianbin , Long Mingzhu 
Published: October 2020

Abstract
The methylammonium (MA) and formamidinium (FA) are the most commonly used organic cations in perovskite solar cells (PSCs), whereas the impact of size and polarity differences between these two on the photovoltaic performances has been rarely revealed. Herein, we systematically investigated the phase distribution, optoelectronic and stability properties of FA-MA mixed perovskites. To identify the phase homogeneity, depth-dependent grazing-incidence wide-angle x-ray scattering measurements were employed, which demonstrates that the mixed cation perovskite possesses a FA-rich phase on the film surface and the bottom is comprised of MA-rich phase. Additionally, upon long-time illumination, a new PL peak is appeared at 778 nm, representing the generation of MA-rich phase induced by ion migration. It is worth noting that the phase splitting and inhomogeneous phase distribution would not bring any obvious detrimental effects to the photovoltaic performances and stability properties. Through judiciously tuning the cation proportion in pure-iodide perovskite, the additive-free PSCs achieve an efficiency as high as 20.7%. Furthermore, the PSCs with a broad range of FA/MA ratios show improved humidity/thermal/light stability despite the phase inhomogeneity. Therefore, the work shows that the MA and FA cations have a high compatibility in perovskite structure and the precise ratio control can further improve the performances.
Spatiotemporal dynamics of a predation system with time delay and spatial diffusion
Authors: Rao Feng , Luo Junling , Zhang Zhongliang , Kang Yun 
Published: October 2020

Abstract
This paper investigates the spatiotemporal dynamics of a Monod–Haldane type predator–prey interaction system that incorporates: (1) a time delay in the predator response term in the predator equation; and (2) diffusion in both prey and predator. We provide rigorous results of our system including the asymptotic stability of equilibrium solutions and the existence and properties of Hopf bifurcations with or without time delay and diffusion. The effect of diffusion on bifurcated periodic solutions is investigated. We show that analytically and numerically at a certain value the carrying capacity or time-delay-driven stability or instability occurs when the corresponding system has either a unique interior equilibrium or two interior equilibria. Moreover, we illustrate the spatial patterns out of an initially nearly homogeneous state via numerical simulations, which show that the system dynamics exhibits complex pattern replication: spiral wave patterns and chaotic spiral patterns by increasing the control parameter K and time delay τ respectively. In addition, we obtain further spiral patterns with different initial conditions. These results indicate that the carrying capacity and time delay play an important role in pattern selection. Our results may provide useful biological insights on population management for predator–prey interaction systems.
Elastic changes in luminescence intensity of vitrified film of europium(III) β-diketonate complex
Authors: Lapaev D V , Nikiforov V G , Lobkov V S , Knyazev A A , Ziyatdinova R M , Galuametdinov Yu G , Samartsev V V 
Published: October 2020

Abstract
We have observed an elastic change in luminescent properties of a 20 µm thick vitrified film (prepared from an amorphous powder of an anisometric europium(III) β-diketonate complex through a melt-processing technique and sandwiched between two quartz plates) caused by the prolonged UV irradiation. The film under UV light irradiation exhibits a typical Eu3+ ion emission peaked at 611 nm. The irradiation of the film by a 337 nm pulsed nitrogen laser with 0.2 mW average output power for 80 min leads to 1.5-fold decrease in the luminescence intensity at 611 nm. Despite the fact that in the case of traditional film-type materials based on lanthanide(III) β-diketonate complexes such effect is attributed to irreversible ligand photofragmentation, we have observed no photodecomposition of the anisometric complexes in the vitrified film. Moreover, we detected full reversibility of the luminescence intensity by keeping the film in the dark for 21 h. It is worth noting that this feature can be used for the design of new reusable luminescent dosimeters for UV light.
Monitoring of the luminescence properties of the upconversion YVO4:Yb, Er nanoparticles during preparation processes
Authors: Zharkov D K , Shmelev A G , Latypov I Z , Leontyev A V , Nikiforov V G , Lobkov V S , Fedotov I V , Alkahtani M H , Hemmer P R , Samartsev V V , Zheltikov A M 
Published: October 2020

Abstract
We have fabricated the upconversion nanoparticles (NPs), which are nanocrystallites of 10 nm, doped with Yb3+ and Er3+ ions, prepared through hydrothermal method. Monitoring of their photophysical properties had been realized at different fabrication stages by using electron microscopy and luminescence spectroscopy under photoexcitation of the NPs with the 100 mW laser at 980 nm wavelength. The performed monitoring allows us to observe dramatic changes in the upconversion properties of the NPs during the sequence of the fabrication stages and revealed very strong correlation between the NPs’ upconversion efficiency and their structural specificities.
Non-linear hydroelastic response of a monopile foundation in regular waves
Authors: Leroy Vincent , Bachynski Erin E. , Gilloteaux Jean-Christophe , Babarit Aurélien , Ferrant Pierre 
Published: October 2020

Abstract
This paper presents an original contribution to the coupled hydroelastic simulation of offshore wind turbines foundations. A non-linear coupled simulation tool has been developed to calculate the response of these systems. The hydrodynamic loads are computed by the non-linear potential flow solver WSCN, developed at Centrale Nantes and based on the weak-scatterer theory. The response of the structure is calculated with a finite element analysis tool using an Euler-Bernoulli beam model. The two solvers are tightly coupled. A first case study is presented here. It consists of a uniform monopile foundation in regular waves. Numerical simulations are compared to results obtained with the SIMA software, which uses Morison equation and non-linear wave kinematics. The two simulation tools show a very good agreement in a series of regular waves up to the third-order load harmonic. Higher-order harmonics appear with WSCN in steep waves, which are not computed by SIMA.
Wave-induced collision loads and moments between a spar-buoy floating wind turbine and an installation vessel
Authors: Lande-Sudall D R , Høyven T S , Herfjord K , Thuestad T C 
Published: October 2020

Abstract
Spar-buoy floating wind turbines (FWTs) have been deployed at full-scale off the coast of Scotland. However, their deep draught restricts their wider-suitability for assembly and installation at shallow water ports. Here a barge-type installation vessel is investigated experimentally for supporting a FWT such that a draught reduction of up to 30% can be achieved. Tests in irregular waves are conducted to understand the design loads required of a mechanical linkage between the vessel and FWT. Overturning moments increase by over double for a doubling in significant wave height, Hs
, and peak overturning moment occurs at the pitch eigenfrequency of the combined vessel and FWT. For Hs
=1.5 m, these loads can be accommodated for with a steel truss-frame structure. Collisions between vessel and FWT are also tested for regular head waves and show that, whilst a number of collision forces exceed those of the relevant design standards, these could be reduced to within the existing design limits by use of a fender.
Validation of drift motions for a semi-submersible floating wind turbine and associated challenges
Authors: Mahfouz M Y , Faerron-Guzmán R , Müller K , Lemmer F , Cheng P W 
Published: October 2020

Abstract
In the EU H2020 project LIFES50+, a 1:36 scaled model test campaign was carried out for the NAUTILUS-DTU10 semi-submersible floating offshore wind turbine with active ballast. This paper concentrates on the modelling capabilities of a state-of-the-art time domain simulation model FAST8 for floating offshore wind turbines and specific challenges associated with the validation process. For the modelling, the platform is considered as a rigid body, and the frequency dependant radiation damping, added mass, and wave excitation are evaluated with a panel code using potential theory. The results from the scaled model are compared to the simulations, looking into the effects on the platform when the first order radiation-diffraction hydrodynamics through the Cummins equation, the mean drift coefficients from the nearfield solution for Newman’s approximation of the second-order difference-frequency wave forces, and full quadratic transfer function (QTF) are taken into account. Moreover, viscous forces on the floating platform are modelled through Morison elements with coefficients of drag. Frequency domain analysis of the motions showed good agreement after modifications of the coefficients of drag of the Morison elements for tests performed with a pink wave spectrum. On the other hand, the extreme wave test showed large discrepancies between results and simulations, which could not be overcome by the inclusion of the QTFs or tuning of the coefficients of drag which model the viscous forces. This is followed by a discussion of the challenges in the modelling approach, and other validation techniques are proposed for future research. The main goal is to define the Morison elements for the floater, and tune the drag coefficients to enable the numerical tool to capture the floater’s motions. The effect of the change of the coefficients on the simulation outputs are shown.
Numerical Modelling of the MIT/NREL TLP Wind Turbine and Comparison with the Experimental Results
Authors: Vardaroglu M , Gao Z , Avossa A M , Ricciardelli F 
Published: October 2020

Abstract
In this study, numerical analysis of a tension leg platform wind turbine is conducted and the responses with focus on surge motions and tendon tension are compared with available experimental test data. The main scope of the study is to establish the numerical model for which the damping coefficients for rigid-body motions are tuned based on the comparison of the sway free decay test results (natural periods and damping ratios) between the numerical and the experimental studies. The differences between the test model properties and the numerical model information have been discussed. Numerical model tuning with available test data resulted with relatively good accordance but also slight to moderate differences in the responses. These differences are credited for the uncertainties in the model testing and the solution methodology of the numerical model. Numerical study is under development with regular and irregular wave analyses and analyses including wind excitation.
Sensitivity analysis of cost parameters for floating offshore wind farms: an application to Italian waters
Authors: Maienza C , Avossa A M , Ricciardelli F , Coiro D , Georgakis C T 
Published: October 2020

Abstract
Floating offshore wind farms represent the next frontier in wind power industry. However, the development of this technology is strongly dependent on its economic feasibility. There follows that the development of economic analyses is crucial to highlight the possible greater potential of floating offshore wind farms and to support their sustainability and technical value.
In this context, the purpose of this paper is to present a sensitivity analysis of the main cost parameters for floating offshore wind farms, namely the distance from the coast, the distance from the closest port and the sea depth. It can give specific information on which parameters are more important, and how much they affect the total cost.
To this aim, a comprehensive life cycle cost assessment of floating offshore wind farms has been developed. In this study the cost model has been applied to the Italian waters.
The results shown should provide guidance on how to preliminary assess the quality of a given site for floating offshore wind farm installation, and should be helpful for future development of decision-making procedures in the offshore wind sector.