bluuebunny/crossref_metadata_2025 huggingface dataset:
High performance TADF-phosphorescence hybrid warm-white organic light-emitting diodes with a simple fully doping-free device structure
Authors: Xue Chuang , Zhang Gang , Jiang Wenlong , Lang Jihui , Jiang Xin
Published: October 2020

White organic light-emitting diodes (WOLEDs) with doping-free emissive layer (EML) structures have been increasingly attracting attention due to their excellent advantages, such as easier manufacturing process and more flexible structure design. In this paper, a series of highly efficient hybrid WOLEDs is manufactured using a simple doping-free EML structure, which is composed of two blue thermally activated delayed fluorescence (TADF) emitters and an ultrathin (<0.1 nm) orange phosphorescent emitter. Through the thickness optimization of the blue TADF emitters, the optimal device shows a maximum external quantum efficiency, power efficiency, current efficiency, and luminance of 9.1%, 22.7 lm/W, 29.0 cd/A, and 14 530 cd/m2, respectively. When the brightness is increased from 1000 cd/m2 to 10 000 cd/m2, the chromaticity coordinates migrate from (0.44, 0.48) to (0.41, 0.47), and the correlated color temperature changes from 3454 to 3881 K, which belongs to the warm-white light emission zone. The result indicates that the use of a doping-free blue–orange–blue structure provides a common path for fabricating efficient, simple, and low cost WOLEDs.
Ecosystem structure and resilience of the Florida Bay Estuary: an original ecosystem model with implications for everglades restoration
Authors: Smith Mason , Chagaris David , Paperno Richard , Markwith Scott
Published: October 2020

Restricted from its historic freshwater input from the Everglades, the Florida Bay estuary is plagued by hypersaline conditions and disturbances such as aperiodic seagrass die-off events. One of the largest restoration efforts in the US, the Comprehensive Everglades Restoration Plan (CERP) aims to restore the freshwater inputs lost. Providing world-renowned recreational fishing opportunities and nursery habitat for valuable commercial fisheries, the bay’s condition, coupled with the potential changes from CERP and future climate, highlight the need to implement an ecosystem-based management (EBM) approach. We developed a comprehensive ecosystem model of Florida Bay using Ecopath with Ecosim to provide a thorough understanding of its structure and resilience to environmental disturbances. The results supported the hypothesis that the bay is stabilised through detrital pathways but is not driven primarily through bottom-up control as predicted. Several predator–prey relationships are identified for suggested ecological attention in fisheries management, including the ecological benefits of the forage species pink shrimp, clupeids, pinfish and mullets, and a negative top-down effect of common snook on red drum. The results further support the hypothesis that the restoration of freshwater flows will improve overall resilience in Florida Bay, namely by providing a regime of lower salinity and reduced nutrient enrichment.
And will birds sing? A biography of Julie Savidge
Authors: Kennedy Patricia L.
Published: October 2020

Julie Savidge was among the first small but significant tranche of women field biologists. Her PhD research on the Pacific Island of Guam, published in 1987, stands as a textbook example of ecological problem solving and the first example of the devastating impact of an introduced reptile on an island fauna, the consequences of which continue today. Yet, her findings initially were strongly and publicly challenged. This paper is a brief biography of Julie, as one of the more successful of those pioneer women conservation biologists to work in the Pacific region. It tracks her early life, her influences and career path, and her struggles to balance work and family, particularly in the stressful world of academia.
Causes and consequences of asymmetric lateral plume flow during South Atlantic rifting
Authors: Morgan Jason P. , Taramón Jorge M. , Araujo Mario , Hasenclever Jörg , Perez-Gussinye Marta
Published: October 2020

Significance

This article tackles the longstanding question of why some continental rifting was associated with major pulses of excess volcanism that formed “volcanic rifted margins,” yet other rifting, even nearby, was not. After reviewing the South Atlantic rifting exemplar, we present results from an improved type of three-dimensional calculation of mantle flow that avoids many of the artificial boundary condition-related pitfalls in prior numerical studies that did not predict asymmetric rift-related volcanism. Our experiments match the observed development of asymmetric volcanism during South Atlantic rifting, with important implications for plume-influenced rifting of continents. In particular, the scenario does not require a conventionally assumed “starting plume head” to provide the hotter-than-average mantle that induces excess rift magmatism.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Optimization-based calibration of hydrodynamic drag coefficients for a semisubmersible platform using experimental data of an irregular sea state
Authors: Böhm M , Robertson A , Hübler C , Rolfes R , Schaumann P
Published: October 2020

For the simulation of the coupled dynamic response of floating offshore wind turbines, it is crucial to calibrate the hydrodynamic damping with experimental data. The aim of this work is to find a set of hydrodynamic drag coefficients for the semisubmersible platform of the Offshore Code Comparison Collaboration, Continuation, with Correlation and unCertainity (OC6) project which provides suitable results for an irregular sea state. Due to the complex interaction of several degrees of freedom (DOF), it is common to calibrate drag coefficients with the time series of decay tests. However, applying these drag coefficients for the simulation of an irregular sea state results in misprediction of the motions. By using numerical optimization, it is possible to calibrate multiple drag coefficients simultaneously and effectively, while also considering several DOF. This work considers time series of structural displacements from wave tank tests of the OC6 project and from simulations of the same load cases in OpenFAST. Results are transferred into the frequency domain and the deviation between power spectral densities of surge, pitch and heave from experiment and numerical simulation is used as an objective function to obtain the best fitting drag coefficients. This novel numerical optimization approach enables finding one set of drag coefficients for different load cases, which is a major improvement compared to decay-test-tuned drag coefficients.
Dependence of Floating LiDAR performance on external parameters – Are existing onshore classification methods applicable?
Authors: Wolken-Möhlmann Gerrit , Gottschall Julia
Published: October 2020

Floating LiDAR is a new aspiring technology for replacing offshore meteorological masts for applications like offshore site assessment or power curve measurement. Since the beginning of the development of the first Floating LiDAR Systems (FLS) in the late 2000s, the systems are more and more maturing. The focus of current research is moving from the pure technology development to the application of the obtained data. As a result, procedures for assuring the measurement quality and the assessment of the data quality - or the quantification of estimated measurement uncertainty, respectively - is a key aspect for further increasing the confidence in the data. This is an important pillar for a further distribution of the technology, and for decreasing risks and costs for its application in offshore wind.

In this paper, we introduce the methodologies of FLS verification and classification, with the goal to verify the measurement of individual FLS and study the characteristics of a certain type of LiDAR systems. A classification case study is presented, showing low effects of the buoy motion and sea states on the FLS measurement for the Fraunhofer LiDAR buoy. A detailed study of the interdependencies between influencing parameters and the possible correlations is presented as well.

The robustness and issues of the classification methodology - originally defined for fixed LiDAR systems - is discussed. Especially the non-robustness of the bin-fitting is identified as an issue. Alternative methods for the sensitivity analysis within the classification process are discussed.
A study of radiation tolerance in optical cements
Authors: Tesarek R.J. , Hahn E. , Pla-Dalmau A. , Jr. J.L. Salinas , Wenzl D.
Published: October 2020

We study the effect ionizing radiation has on light transmission in the wavelength range 190–1100 nm for a number of optically clear epoxies. We find that the transmittance of traditional, commercially available, optical epoxies show significant degradation for exposures of 1×1012MIPs/cm2. Degradation of light transmission progresses from the shortest wavelengths at low doses to longer wavelengths as the dose increases. In epoxy joints that are 0.1 mm thick, we observe that more than 5% of the light is lost for wavelengths less than 400 nm for traditional optical epoxies. Our studies have identified an optically clear epoxy that shows little degradation for radiation exposures up to 5.9× 1014MIPs/cm2(≈ 220 kGy).
Impacts of urbanization, antecedent rainfall event, and cyclone tracks on extreme floods at Houston reservoirs during Hurricane Harvey
Authors: Li Xudong , Zhao Gang , Nielsen-Gammon John , Salazar Joel , Wigmosta Mark , Sun Ning , Judi David , Gao Huilin
Published: October 2020

The objective of this study is to evaluate the effects of urbanization, an antecedent rainfall event (ARE), and varying cyclone tracks on the streamflow—and thus the subsequent reservoir status—during the floods caused by Hurricane Harvey in August–September 2017. Through a hydrological modeling approach, we examined how these factors influenced the inflows, peak pool elevations, and outflows of the two most important detention reservoirs in the Houston region, the Addicks and Barker Reservoirs. A high-resolution rainfall reanalysis dataset for extreme storm events, along with a suite of synthetic rainfall values from a variety of storm tracks, were adopted to represent both the truth and the maximum possible rainfall during the Hurricane Harvey period. The results showed the following: Urbanization only led to slight increases in peak inflows, not necessarily to an increase in peak pool elevations, and the ARE contributed to the peak inflow and pool elevation slightly. In contrast, if the cyclone had followed the most adverse track consistent with earlier forecasts (all else being equal), the total volumetric flow into the two reservoirs would have been significantly larger (37% and 49% respectively), thus increasing the peak pool elevations by 1.06 and 1.37 m respectively. These results suggest that large uncertainties exist for flood management at a watershed scale during hurricanes, because of the uncertainties in the cyclone track. This would remain true even if storm-relative precipitation rates could be predicted perfectly.
Determination of thermal parameters of a shell and tube heat exchanger with increased turbulization of the working fluid
Authors: Nikulin N Yu , Kushchev L A , Feoktistov A Yu
Published: October 2020

Shell and tube heat exchangers are still widely used. This equipment is widely used in heat supply systems, food, chemical and petroleum industries. Therefore, conducting research to improve their performance is an important area. By changing the geometry of the heat exchange surface, the flow of the working fluid is further turbulated and the heat exchange area increases. The heat exchanger with a developed heat exchange surface is proposed, which differs from the serial device (with smooth tubes). Thus, a plate equipped with a cylindrical edge is installed on the heat exchange tube. The working fluid in the inter-tube space, flowing around the edges, is turbulated. This reduces the thickness of the laminar sublayer on the plate and edge. Accordingly, the heat transfer from the heat exchange surface to the streamlined fluid increases. When new elements appear in the design of the heat exchange surface, it is necessary to develop the calculation of temperature parameters for these surfaces. Formulas for calculating the average surface temperature of the edge and plate under conditions of turbulent flow around these surfaces are obtained analytically. The temperatures of the plate and edge will determine the Prandtl criterion Pr. In the future, this is necessary to find the main parameter of the heat exchanger – the heat transfer coefficient.
Simulation of accelerated concrete destruction by inoculation of an association of bacteria of the genus Thiobacillus
Authors: Fomina E V , Sverguzova S V , Goncharova E N , Flores-Vivián I
Published: October 2020

The mechanisms of biogenic destruction of concrete under the influence of microbiological corrosion are described. An accelerated method of inoculation of the association of sulfur-oxidizing thionic bacteria Thiobacillus thioparus and Thiobacillus thiooxidans was used. Beyerink solution was used as a nutrient medium. The impact of two types of microorganisms in model systems imitates microbiocorrosion conditions; this allows reducing the test time and predicting the mechanisms of concrete destruction during operation. The active development of Thiobacilus thioparus promotes the leaching of concrete, further bacteria of the genus Thiobacilus thiooxidans appear with a decrease in pH, and both species actively synthesize sulfuric acid. The kinetics of the bio corrosion process was monitored for 60 days. The bacterial adaptation period is 16–18 days, after which the pH of the aqueous medium decreases. The rate of formation of a biological acid in an aqueous medium determines the leaching of Mg2+, Ca2+, and

SO

4

2
−

ions from concrete. Concrete when exposed to bio acids for two months loses 30% of its strength. The microstructure analysis of bio corrosion products on the concrete surface was carried out with the help of a scanning electron microscope.
Finishing materials in construction using polymer composites
Authors: Klyuchnikova N V , Klepikova M A , Denisova L V
Published: October 2020

Polymer composite materials are increasingly replacing traditional composites such as wood, metal, and natural fibers from the world market of building materials. Polymer composite materials are widely used in the construction industry. Currently, the development of advanced polymer-based composites is a very relevant area. The promising method for modification of epoxy polymer composite with mineral filler schungite is considered. It was found that the introduction of mineral filler increases the composite resistance to impact forces. It is proved that schungite-filled epoxy composites have increased strength and performance properties, which is very important when they are used in the construction industry. After carrying out a number of physical, mechanical and operational studies, it can be concluded that polymer composite materials based on ED-20 resin with the content of mineral filler shungite have the best performance, compared to non-filled composite materials. Thus, the resulting PCM can be used in the construction industry as a finishing material, as it has the necessary complex of strength and performance properties.
Obtaining sorption material from sorghum for aqueous solutions purification from heavy metals
Authors: Fomina E V , Sverguzova S V , Sapronova ZH A , Kozhukhova M I
Published: October 2020

The paper presents the results of using straw (stalks) of sorghum as a sorbent for removing heavy metal ions of Cu (II) from aqueous solutions. The physical and chemical analysis of sorghum has been carried out. The modification of plant materials by exposure to a temperature of 130-150 ° C is proposed. Thermal activation allows obtaining a highly developed surface of the sorghum microstructure and increasing the total pore volume and their average diameter. The regularities of the effect of the concentration of the modified sorbent and the differences of its dispersed particles on the efficiency of water purification are investigated. The purification of an aqueous solution containing 50 mg/dm3 of Cu2+ ions was 95% under using a thermo-treated sorghum of 0.63–0.1 mm in an amount of 2.5 g per 100 ml of an aqueous solution. Thermal modification of sorghum allows you to get an effective sorbent and immediately solve two environmental problems, such as wastewater treatment and utilization of plant waste.
Sustainability of functioning of enterprises of the building materials industry of the Belgorod region in 2018-2019
Authors: Slabinskaya I A , Benderskaya O B
Published: October 2020

Ensuring the sustainability of functioning under all changes in the economic situation in Russia and in the world continues to be one of the most important goals of managing an enterprise in any sector of the real sector of the economy. This article investigates the stability of the functioning of a sample of the most famous enterprises in the construction materials industry of the Belgorod region: OAO Belgorodasbestocement, ZAO Belgorodskij cement, OAO Belgorodstrojdetal’, OAO Zavod ZHBK-1 and AO Strojmaterialy, using the author’s methods for assessing the stability of functioning. The study period is 2018-2019. The informational basis of the study is the public financial statements of enterprises for 2019. The assessment methodology is based on a system of 12 indicators-indicators of the stability of functioning. For a comparative intercompany assessment of enterprises, the author’s method of calculating a comprehensive assessment was used – a modified method of scoring. Based on the obtained values of comprehensive assessments, stability ratings for the functioning of enterprises for 2018 and for 2019 are compiled.
Investigation of stresses and deformations of ball mill support axles taking into account the temperature field by numerical method
Authors: Bondarenko J A , Duyun T A , Bestuzheva O V
Published: October 2020

In the article, the stresses and deformations of the ball mill support axes are studied numerically, taking into account the temperature field. Expressions are given that determine the values of the stress-strain state of the external surface of the ball mill trunnion, depending on the temperature of the internal and external surfaces. The analysis of the behavior of stresses and deformations when changing the temperature parameters of the trunnion is based on the numerical method. Constant values and parameters of the trunnion are set, and the temperature ranges of the external and internal surfaces of the loading and unloading trunnions are set. A numerical simulation of deformations and stresses is presented, described in the form of dependency graphs with varying parameters-the temperature of the internal and external surface of the trunnion within specified limits. The dependences of stresses and deformations of the external surface on temperature changes are analyzed. It is shown that as the temperature difference increases, the stresses in both the circumferential and axial directions increase, and the deformations in the circumferential and axial directions monotonously increase. The unloading axle is subject to a more complex stress-strain state under the influence of a temperature field, and the external surface of the axle has the highest values of stresses and deformations.
Management mechanisms for resolving organizational conflicts in the context of implementing the economic opportunities of organizations in the construction industry
Authors: Tselyutina T V , Avilova Zh N , Timokhina O A
Published: October 2020

The paper presents a critical analysis of the functional representation of the mechanism for managing social and labor conflicts in the process of organizational changes. Network mechanisms and their functionality in the management system of organizational conflicts are updated. The relationship between the level of staff involvement in work and the level of conflict in the organization is determined. To ensure effective management of organizational conflicts, it is necessary to take into account the level of involvement of the personnel of the organization in processes at different levels, as well as to create conditions and economic methods of motivation that ensure the necessary level of involvement. “Portfolio” of empirical tools for comprehensive research of issues and a mechanism for managing organizational conflicts are developed, taking into account the specifics of the activities of construction organizations.
Portland cement foam concrete with a zeolite-containing mineral additive
Authors: Rozhin V N
Published: October 2020

The possibility of obtaining high-quality cement by an environmentally friendly (without CO2 emission into the atmosphere) method of joint grinding of imported Portland cement clinker and local natural mineral raw materials in hard-to-reach areas of the North-East of the Russian Federation is substantiated. The results of an experimental study of the compositions and technological parameters of the manufacture of cement compositions based on portland cement clinker and active mineral additives from zeolite-containing rocks of Khonguruu, allowing non-autoclaved foam concrete with a density of 600-800 kg / m3 and compressive strength of 1,8-2,8 MPa with stable quality parameters are presented (monodisperse pore distribution and hardened inter-pore skeleton, providing stable values of density, strength and thermal conductivity).
Dynamic test method for full body harnesses exploited in cold climates
Authors: Dmitry Prostakishin , Pham Nam Thanh
Published: October 2020

In this paper, a method of testing the dynamic strength of full body harnesses is proposed. The possibility of conducting the method in laboratory conditions is determined by testing the method while maintaining the specified conditions of low temperatures. The main attention is paid to the effect of the set temperature on the full body harnesses, when dynamic shock loads occur in user operation mode. The advantage of the developed method of dynamic testing of full body harnesses is the simplicity in bringing the test sample to the climatic parameters of operation by pre-conditioning. This makes it possible to implement dynamic testing under specified climatic conditions within mass laboratories in the chain of conformity confirmation. Pre-conditioning allows you to conduct research on the influence of climate factors on various characteristics of safety harnesses. The interaction of the binding elements with each other, previously reduced to the specified temperature parameters, is also studied. It is necessary to pay special attention to the resulting impact loads during dynamic tests, and their relationship when conditioning products at different temperature.
Mixing process simulation of the initial building materials components using the DEM Solution EDEM system
Authors: Samsonova P S , Lozovaya S Y , Bogdanov N E , Lozovoi N M
Published: October 2020

Quality of building materials, products and constructions depends on the organization of technological process of their production, and it, as a rule, concerns preparatory operations, such as crushing and in a greater degree mixing of initial compound components of the future products and constructions. Production of high-quality building mixtures is one of the most actual tasks of modern building technologies. Today, the mixing of bulk materials has evolved into a special branch of technological knowledge, which is based on mechanical processes, whose goal is to ensure the highest possible degree of alignment of individual components in the mixture. Due to the development of digital technology, modern industry is able to abandon expensive and long field experiments and tests in favor of digital experiments. The results of digital experiments have a high degree of convergence with real experiments, but are carried out many times faster. To model the influence of the material loading method on the heterogeneity factor of the mixture, digital sampling was carried out using EDEM software in a screw type mixer.