bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationships between impact performance and structures of rotationally molded crosslinked high‐density polyethylene
Authors: Ren Yueqing , Sun Xiaojie , Li Yafei , Chen Lanlan , Sun Miaomiao , Liang Wenbin 
Published: November 2020

AbstractCrosslinked high‐density polyethylene (XL‐HDPE) is a preferred material for chemical and fuel tanks due to its superior environmental stress crack resistance and impact strength. The impact performance of rotationally molded specimen is important for final products. In the research the drop weight impact strength (defined as ARM impact strength) of rotationally molded XL‐HDPE is tested between −40°C and 25°C. The crosslinking content, crystallization characteristics, and dynamic mechanical properties (DMA) of different thickness gradients are examined to illustrate the relationships between the impact strength, brittle‐ductile transition (BDT) and microstructures. The innermost surface layer (about 0.3 mm) has lower gel content, higher crystallinity, and average lamellar thickness compared with the body part. The ARM impact strength is about 1 J/mm at −40°C and −30°C, and about 29 J/mm at −20°C ~ 25°C. There is a BDT between −30°C and − 20°C. After removing the innermost surface layer, the sample breaks in ductile manner in the entire tested temperature range, and the ARM impact strength is about 24 ~ 26 J/mm. The DMA results show that the BDT is consistent with the structure transition of the innermost surface layer. The microstructures of rotationally molded XL‐HDPE in the innermost surface layer dominate the low temperature impact performance.
Measuring the dynamic response of the thylakoid architecture in plant leaves by electron microscopy
Authors: Li Meng , Mukhopadhyay Roma , Svoboda Václav , Oung Hui Min Olivia , Mullendore Daniel L. , Kirchhoff Helmut 
Published: November 2020

AbstractThe performance of the photosynthesis machinery in plants, including light harvesting, electron transport, and protein repair, is controlled by structural changes in the thylakoid membrane system inside the chloroplasts. In particular, the structure of the stacked grana area of thylakoid membranes is highly dynamic, changing in response to different environmental cues such as light intensity. For example, the aqueous thylakoid lumen enclosed by thylakoid membranes in grana has been documented to swell in the presence of light. However, light‐induced alteration of the stromal gap in the stacked grana (partition gap) and of the unstacked stroma lamellae has not been well characterized. Light‐induced changes in the entire thylakoid membrane system, including the lumen in both stacked and unstacked domains as well as the partition gap, are presented here, and the functional implications are discussed. This structural analysis was made possible by development of a robust semi‐automated image analysis method combined with optimized plant tissue fixation techniques for transmission electron microscopy generating quantitative structural results for the analysis of thylakoid ultrastructure.Significance StatementA methodical pipeline ranging from optimized leaf tissue preparation for electron microscopy to quantitative image analysis was established. This methodical development was employed to study details of light‐induced changes in the plant thylakoid ultrastructure. It was found that the lumen of the entire thylakoid system (stacked and unstacked domains) undergoes light‐induced swelling, whereas adjacent membranes on the stroma side in stacked grana thylakoid approach each other.
Development, characterization and modeling of mosquito repellent release from microporous devices
Authors: Sitoe Alcides , Mapossa António B. , Focke Walter W. , Muiambo Herminio , Androsch René , Wesley‐Smith James 
Published: November 2020

AbstractNanocomposite strands with mosquito repellent DEET or Icaridin incorporated in a poly(ethylene‐co‐vinyl acetate) (EVA) matrix, with either pyrogenic silica or an organoclay as a nanofiller, were prepared by a twin‐screw extrusion compounding technique. The nature and levels of the repellent and nanofiller that was used affected the material phase morphology. The repellent release was followed as a function of aging time in convection ovens set at 30 and 50°C. The experimental release data of the mosquito repellent from the microporous polymer swellable matrix strands was mathematically modeled and fitted using a range of semi‐empirical models. In the majority of case, the Korsmeyer‐Peppas power law model provided the best data fit. As expected, the wide range of internal morphologies also resulted in quite different release profiles. These models were found to be valuable as they provided insights into the mechanism of repellent release from EVA swellable matrices. It was possible to differentiate between diffusion and relaxation mechanisms. Surprisingly, strands containing nominally more than 30 wt% Icaridin showed accelerating mass loss during the initial phase, consistent with Super Case II transport. Diffusional exponents as high as 1.81 were found. Furthermore, the internal microporous region of the extruded EVA strands was covered by a surface membrane that acted a diffusion barrier that, in effect, controlled the release rate of the mosquito repellents. Some of the investigated samples exhibited release profiles that suggest that longer lasting effective release of repellents is possible than currently achieved by available commercially products.
A Narrative Review of Metatarsal Bone Stress Injury in Athletic Populations: Etiology, Biomechanics, and Management
Authors: Troy Karen L. , Davis Irene S. , Tenforde Adam S. 
Published: November 2020

AbstractMetatarsal bone stress injuries (BSIs) are common in athletic populations. BSIs are overuse injuries that result from an accumulation of microdamage that exceeds bone remodeling. Risk for metatarsal BSI is multifactorial and includes factors related to anatomy, biology, and biomechanics. In this article, anatomic factors including foot type, metatarsal length, bone density, bone geometry, and intrinsic muscle strength, which each influence how the foot responds to load, are discussed. Biologic factors such as low energy availability and impaired bone metabolism influence the quality of the bone. Finally, the influence of biomechanical loads to bone such as peak forces, load rates, and loading cycles are reviewed. General management of metatarsal BSI is discussed, including acute care, rehabilitation, treatment of refractory metatarsal BSI, and evaluation of healing/return to sport. Finally, we identify future research priorities and emerging treatments for metatarsal BSI.
Design of ketone derivatives as highly efficient photoinitiators for free radical and cationic photopolymerizations and application in 3D printing of composites
Authors: Xu Yangyang , Ding Zhaofu , Zhu Haibin , Graff Bernadette , Knopf Stephan , Xiao Pu , Dumur Frédéric , Lalevée Jacques 
Published: November 2020

AbstractHerein, thirteen ketone derivatives composed of different cyclohexanone cores and peripheral moieties are designed, among which 10 ketones have never been synthesized before. These ketones are proposed as high‐performance photoinitiators for both free radical polymerizations and cationic polymerizations under soft conditions (visible LED@405 nm irradiation at room temperature). In combination with an amine and an iodonium salt (Iod), these ketones could be used in three−component photoinitiating systems to initiate the free radical polymerization of acrylates with distinct final conversions, among which the ketone−1/amine/Iod combination proved to be the most efficient one. Besides, the ketone−1/Iod two−component system also showed a remarkable photoinitiation ability for the cationic polymerization of epoxides. The photochemical sensitivity of ketone−1 in the presence of an amine and an iodonium salt was systematically investigated by steady state photolysis and excited state fluorescence quenching characterizations, respectively. Interestingly, macroscopic 3D patterns with excellent spatial resolution could be generated using the ketone−1/amine/Iod photoinitiating system for the free radical polymerization of acrylates. This high performance is also found useful to overcome the light penetration issue for the access to filled samples (silica) and the preparation of composites.
Gibberellic acid decreases Melanocallis caryaefoliae (Hemiptera: Aphididae) population density and chlorotic feeding injury to foliage in pecan orchards
Authors: Cottrell Ted E , Wood Bruce W 
Published: November 2020

AbstractBACKGROUNDMelanocallis caryaefoliae (Davis), Monellia caryella (Fitch), and Monelliopsis pecanis Bissell (Hemiptera: Aphididae) attack pecan foliage (Carya illinoinensis [Wangenh.] K. Koch). Unlike M. caryella and M. pecanis, feeding by M. caryaefoliae triggers a physiological change within foliage mimicking natural leaf senescence; it can lead to defoliation. Pretreatment of pecan foliage with gibberellic acid (GA3) mitigates M. caryaefoliae‐elicited physiological disturbances. GA3 application to pecan was evaluated for efficacy regarding effects on M. caryaefoliae populations and possible negative side‐effects on two natural enemy species and on return bloom of pecan.RESULTSAll GA3 treatment rate schedules significantly reduced M. caryaefoliae nymphs but not adults or adults and nymphs of M. caryella or M. pecanis. Percentage leaf chlorosis elicited by M. caryaefoliae was significantly reduced by GA3 (i.e., 39.5 to 197.7 g a.i./ha). No negative side‐effects of GA3 treatment were detected regarding certain key natural enemy species or on return bloom of pecan.CONCULUSIONApplication of GA3 to the orchard canopy protects foliage from senescence‐like physiological responses triggered by M. caryaefoliae. This reduces detrimental leaflet chlorosis, both senescence and abscission processes and horticulturally significant feeding injury. Additionally, the absence of apparent negative side‐effects on key natural enemies and return bloom is suggestive of a practical means for efficacious non‐insecticidal control of M. caryaefoliae populations in orchards. This novel protective effect of GA3 against aphid‐elicited, senescence‐like physiological responses may merit investigation as an IPM tool to manage aphid species eliciting similar senescence‐like damage to other crop species. Published 2020. This article is a U.S. Government work and is in the public domain in the USA.
The information theory of the helium atom in screened Coulomb potentials
Authors: Martínez‐Flores César 
Published: November 2020

AbstractIn this work, we show Hartree–Fock (HF) results for the Shannon entropy, Rényi entropy, Tsallis entropy, Onicescu information energy, and ground‐state properties of the helium atom in screened Coulomb potentials. We solve the HF equations through a numerical grid method where the screened functions model two plasma environments: the Debye–Hückel screening (DHS) and the exponential‐cosine‐screened‐Coulomb (ECSC) model potentials. For plasma conditions near to the energy ionization, for the Shannon entropy, we report an increase of the ∼80% and ∼60% for the DHS and ECSC potentials concerning the unscreened case. A similar situation is found for the Rényi and Tsallis entropies where an increase of ∼86% and ∼57% is reported in the presence of the DHS and ECSC potential functions. Our results allow us to obtain knowledge of the information theory parameters in the description of the electron localization for the helium atom screened by the DHS and ECSC potentials. Finally, our information theory findings in the absence of the screening functions are in excellent agreement with the available results found in the literature.
Robust observer‐based controller for uncertain‐stochastic linear parameter‐varying (LPV) system under actuator degradation
Authors: Do Manh‐Hung , Koenig Damien , Theilliol Didier 
Published: November 2020

SummaryThe main contribution of this article is a new methodology of a polytopic observer‐based controller in estimating and accommodating polynomial actuator degradation for uncertain stochastic linear parameter varying system. In this design, robust observer‐based controller gains are synthesized with a unique linear matrix inequality solution such that the impact of disturbance on observer estimation is attenuated by a frequency‐shaping filter, while ensuring the closed‐loop stability against system uncertainties and stochastic noise. Finally, an example is illustrated to highlight the performance of the proposed method.
Predicted effects of flow diversion by Run‐of‐River hydropower on bypassed stream temperature and bioenergetics of salmonid fishes
Authors: Gibeau Pascale , Palen Wendy J. 
Published: November 2020

AbstractMany anthropogenic disturbances impact stream ecosystems by changing flow and temperature regimes. The emerging industry of small Run‐of‐River (RoR) hydropower reduces streamflow in bypassed reaches, with largely unknown consequences for water temperatures and fish growth. We used empirical and simulated data from two small RoR regulated streams in British Columbia (Canada) to quantify changes in water temperatures in bypassed reaches and assess the potential impacts to resident rainbow trout (Oncorhynchus mykiss) growth using bioenergetics models under a range of consumption scenarios. We found increases in mean monthly water temperature in bypassed reaches due to flow diversion of 0.5–0.8°C (0.17–0.19°C/km). Bioenergetics models using those temperatures predicted increases in annual O. mykiss growth (compared to natural temperatures) if consumption was unlimited (+200–450%), increases (+15–42%) if consumption was scaled with higher metabolic demand, and small reductions (−5 to 7%) if consumption remained constant. If food availability was reduced by 25%, annual growth was predicted to decline by 45%. Empirical estimates of annual growth of fish sampled indicate modest reductions in annual growth less severe than those modelled by our Scenario 2. Our results highlight that increases in water temperature induced by flow diversion for small RoR hydropower could be large enough to have consequences for O. mykiss growth, but the impacts depend on how and when RoR hydropower affects food supply and consumption.
Metal–Organic Framework‐Derived Co3V2O8@CuV2O6 Hybrid Architecture as a Multifunctional Binder‐Free Electrode for Li‐Ion Batteries and Hybrid Supercapacitors
Authors: Sekhar S. Chandra , Ramulu Bhimanaboina , Narsimulu D. , Arbaz Shaik Junied , Yu Jae Su 
Published: November 2020

AbstractMetal–organic frameworks (MOFs) are promising materials in diverse fields because of their constructive traits of varied structural topologies, high porosity, and high surface area. MOFs are also an ideal precursor/template to derive porous and functional morphologies. Herein, Co3V2O8 nanohexagonal prisms are grafted on CuV2O6 nanorod arrays (CuV‐CoV)‐grown copper foam (CF) using solution‐processing methods, followed by thermal treatment. Direct preparation of active material on CF can potentially eliminate electrochemically inactive and non‐conductive binders, leading to improved charge‐transfer rate. Furthermore, solution‐processing methods are simple and cost‐effective. Owing to versatile valence states and good redox activity, the vanadium‐incorporated mixed metal oxides (CuV‐CoV) exhibited superior electrochemical performance in lithium (Li)‐ion battery and supercapacitor (SC) studies. Furthermore, hollow carbon particles (HCPs) derived from MOF particles (MOF‐HCPs) are used as the anode material in SCs. A hybrid SC (HSC) fabricated with CuV‐CoV and MOF‐HCP materials exhibited noteworthy electrochemical properties. Moreover, a solid‐state HSC (SSHSC) is constructed and its real‐time feasibility is investigated by harvesting the dynamic energy of a bicycle with the help of a direct current generator. The charged SSHSCs potentially powered various electronic components.
Accurate In Vivo Nanothermometry through NIR‐II Lanthanide Luminescence Lifetime
Authors: Tan Meiling , Li Feng , Cao Ning , Li Hui , Wang Xin , Zhang Chenyang , Jaque Daniel , Chen Guanying 
Published: November 2020

AbstractLuminescence nanothermometry is promising for noninvasive probing of temperature in biological microenvironment at nanometric spatial resolution. Yet, wavelength‐ and temperature‐dependent absorption and scattering of tissues distort measured spectral profile, rendering conventional luminescence nanothermometers (ratiometric, intensity, band shape, or spectral shift) problematic for in vivo temperature determination. Here, a class of lanthanide‐based nanothermometers, which are able to provide precise and reliable temperature readouts at varied tissue depths through NIR‐II luminescence lifetime, are described. To achieve this, an inert core/active shell/inert shell structure of tiny nanoparticles (size, 13.5 nm) is devised, in which thermosensitive lanthanide pairs (ytterbium and neodymium) are spatially confined in the thin middle shell (sodium yttrium fluoride, 1 nm), ensuring being homogenously close to the surrounding environment while protected by the outmost calcium fluoride shell (CaF2, ≈2.5 nm) that shields out bioactive milieu interferences. This ternary structure enables the nanothermometers to consistently resolve temperature changes at depths of up to 4 mm in biological tissues, having a high relative temperature sensitivity of 1.4–1.1% °C−1 in the physiological temperature range of 10–64 °C. These lifetime‐based thermosensitive nanoprobes allow for in vivo diagnosis of murine inflammation, mapping out the precise temperature distribution profile of nanoprobes‐interrogated area.
Surface Action Spectroscopy: A Review and a Perspective on a New Technique to Study Vibrations at Surfaces
Authors: Liu Y. , Wu Z. , Kuhlenbeck H. , Freund H.‐J. 
Published: November 2020

AbstractA new vibrational spectroscopy method aimed at the investigation of solid surfaces in ultrahigh vacuum, called “Surface Action Spectroscopy (SAS)”, is described and the first results are reviewed. This technique is based on ideas and experiments performed in the gas phase. A surface is exposed to a messenger species at low temperature. This messenger species is desorbed via absorption of tunable infrared light from a free‐electron laser and the desorption rate of the messenger species is recorded via mass spectrometry. It is shown that the technique is extremely surface sensitive and we discuss the basic mechanisms of the technique. We show a feasibility study on a V2O3(0001) surface, where we know the surface structure. We then proceed to the example of iron oxide films to study the surface structure in parallel with calculations of the surface phonons, which allow us to confirm the surface structure of Fe3O4(111) to be Fetet terminated. It also provides evidence for the so‐called biphase structure. To conclude, we discuss possibilities to apply the technique to interesting questions in model and real catalysis, since the technique may provide interesting information independent of long‐range order of the sample.
Development of a novel cognitive composite outcome to assess therapeutic effects of exercise in the EXERT trial for adults with MCI: The ADAS‐Cog‐Exec
Authors: Jacobs Diane M. , Thomas Ronald G. , Salmon David P. , Jin Shelia , Feldman Howard H. , Cotman Carl W. , Baker Laura D. ,   for the Alzheimer's Disease Cooperative Study EXERT Study Group,   for the Alzheimer's Disease Neuroimaging Initiative
Published: November 2020

AbstractIntroductionUse of cognitive composites as primary outcome measures is increasingly common in clinical trials of preclinical and prodromal Alzheimer's disease (AD). Composite outcomes can decrease intra‐individual variability, resulting in improved sensitivity to detect longitudinal change and increased statistical power. We developed a novel composite outcome, the ADAS‐Cog‐Exec, for use in the EXERT trial—a Phase 3 randomized, controlled, 12‐month exercise intervention in mild cognitive impairment (MCI).MethodsThree combinations of cognitive measures selected from the Alzheimer's Disease Assessment Scale‐Cognitive Subscale version 13 (ADAS‐Cog13), tests of executive function, and the Clinical Dementia Rating (CDR) were created based on previously documented sensitivity to longitudinal change in MCI and to the effects of exercise. Optimally weighted composites of each combination were modeled using data from the ADNI‐1 MCI cohort. Ten‐fold cross‐validation was performed to obtain a bias‐corrected mean to standard deviation ratio (MSDR). The cognitive composites were assessed for their sensitivity to detect 12‐month change in MCI.ResultsThe MSDR of 12‐month change for each of the composite outcomes tested exceeded that of the ADAS‐Cog13 total score. The composite with the highest MSDR (MSDR = 0.48) and associated statistical power included scores on ADAS‐Cog13 Word Recall, Delayed Word Recall, Orientation, and Number Cancellation subtests; Trail‐Making Tests A & B, Digit Symbol Substitution and Category Fluency; and cognitive components of the CDR (Memory, Orientation, Judgement & Problem Solving).DiscussionAn optimally weighted cognitive composite measure was identified and validated for use in EXERT. This composite contained selected subtests from the ADAS‐Cog13, additional measures of executive function, and box scores for cognitive components of the CDR. Because this composite score demonstrated high sensitivity to longitudinal change in MCI it will be used as the primary outcome measure for the EXERT trial.
A simple method for modelling fatigue spectra of small wind turbine blades
Authors: Evans Samuel , Dana Scott , Clausen Philip , Wood David 
Published: November 2020

AbstractSmall‐scale wind turbines have market opportunities in distributed energy generation applications but face future challenges in remaining cost competitive compared with solar photovoltaic systems. High unit costs can be attributed to design conservatism when calculating fatigue loads of key structural components such as the blades. In this study, we use the aeroelastic software FAST to highlight limitations of the International Electrotechnical Commission 61400‐2:2013 small wind turbine design standard for calculating fatigue life using the simplified load model. We present a modified method for calculating the fatigue spectra of small wind turbine blades. An advantage of this method is that it does not require complex aeroelastic simulations or field measurements. This modified method is intended to be implemented early in the blade design stage, such as during rotor optimization simulations, allowing for multiple rotor configurations to be rapidly compared.
Probing the Planck scale: the modification of the time evolution operator due to the quantum structure of spacetime
Authors: Padmanabhan T. 
Published: November 2020

Abstract
The propagator which evolves the wave-function in non-relativistic quantum mechanics, can be expressed as a matrix element of a time evolution operator: i.e. GNR(x) = 〈x2|UNR(t)|x1〉 in terms of the orthonormal eigenkets |x〉 of the position operator. In quantum field theory, it is not possible to define a conceptually useful single-particle position operator or its eigenkets. It is also not possible to interpret the relativistic (Feynman) propagator GR(x) as evolving any kind of single-particle wave-functions. In spite of all these, it is indeed possible to express the propagator of a free spinless particle, in quantum field theory, as a matrix element 〈x2|UR(t)|x1〉 for a suitably defined time evolution operator and (non-orthonormal) kets |x〉 labeled by spatial coordinates. At mesoscopic scales, which are close but not too close to Planck scale, one can incorporate quantum gravitational corrections to the propagator by introducing a zero-point-length. It turns out that even this quantum-gravity-corrected propagator can be expressed as a matrix element 〈x2|UQG(t)|x1〉. I describe these results and explore several consequences. It turns out that the evolution operator UQG(t) becomes non-unitary for sub-Planckian time intervals while remaining unitary for time interval is larger than Planck time. The results can be generalized to any ultrastatic curved spacetime.