bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection likelihood of cluster-induced CMB polarization
Authors: Mirmelstein M. , Shimon M. , Rephaeli Y.
Published: October 2020

Nearby galaxy clusters can potentially induce sub-microkelvin polarization signals in the cosmic microwave background (CMB) at characteristic scales of a few arcminutes. We explore four such polarization signals induced in a rich nearby fiducial cluster and calculate the likelihood of their detection by a telescope project with capabilities such as those of the Simons Observatory (SO). In our feasibility analysis, we include instrumental noise, primordial CMB anisotropy, statistical thermal Sunyaev-Zeldovich (SZ) cluster signal, and point source confusion, assuming a few percent of the nominal telescope observation time of an SO-like project. Our analysis indicates that the thermal SZ intensity can be sensitively mapped in rich nearby clusters and that the kinematic SZ intensity can be measured with high statistical significance toward a fast moving nearby cluster. The detection of polarized SZ signals will be quite challenging but could still be feasible toward several very rich nearby clusters with very high SZ intensity. The polarized SZ signal from a sample of ∼20 clusters can be statistically detected at S/N ∼ 3, if observed for several months.
Dust dynamics in planet-driven spirals
Authors: Sturm J. A. , Rosotti G. P. , Dominik C.
Published: October 2020

Context. Protoplanetary disks are known to host spiral features that are observed in scattered light, the ALMA continuum, and more recently in CO gas emission and gas dynamics. However, it is unknown whether spirals in gas and dust trace the same morphology.

Aims. We aim to study the morphology and amplitude of dusty spirals as function of the Stokes number and the underlying mechanisms that cause a difference between dusty spirals and gas spirals. We then construct a model to relate the deviation from Keplerian rotation in the gas to a perturbation in surface density of the gas and dust.

Methods. We used FARGO-3D with dust implementation to numerically study the spirals, after which the results were interpreted using a semi-analytical model. This model was tested on observational data to predict the perturbation of the spiral in gas dynamics based on the continuum data.

Results. We find that the pitch angle of a spiral does not differ significantly between gas and dust. The amplitude of the dust spiral decreases with the Stokes number (St) and starts to fade out at a typical St > 0.1 as the dust becomes decoupled from the gas. The semi-analytical model provides an accurate and fast representation of the difference in the surface density of the spiral in dust and gas. We find a spiral in the TW Hya velocity residual map, never seen before, which is a feature in the vertical velocity and has a kink at the continuum gap, yielding strong evidence for a planet at 99 au.

Conclusions. We built a model that gives an estimate of the underlying dynamics of dust in a spiral, which can serve as evidence of the planetary origin of spirals and can be a probe for the Stokes number in the disk.
Numerical thermal simulation of cryoexposure using Ansys
Authors: Burkov Ivan A. , Pushkarev Aleksandr V. , Shakurov Alexey V. , Tsiganov Dmitry I. , Zherdev Anatoly A.
Published: October 2020

The current advances and problems of medical cryoexposure thermal simulation are considered. Recommendations on improving geometric models, thermophysical properties, boundary conditions, and for parameterizing of the computational domain are proposed. These recommendations can be applied to most modern FEA software packages (tested in Ansys CFX 19.2). Examples of cryoablation and cryotherapy simulation are presented.
Modelling of the operation of a refrigeration unit using radiative cooling to maintain the storage temperature in the cold room
Authors: Tsoy Alexandr P. , Granovsky Alexandr S. , Tsoy Diana A.
Published: October 2020

The results of the research, which show the effect of radiative cooling on the temperature of food storage chamber during the cold season in the cities of Almaty and Kostanay (Kazakhstan) were obtained through computer simulation of the operation cycle. In the installation modelled, pumping circulation of a heat carrier cooled at night in radiators is used. The radiators of the installation cover the entire roof of the cold room (12 m2). Computer simulation shows that the required temperature in the cooled chamber (0 ... + 3 ° C) is maintained in Almaty for 8.5%, and in Kostanay for 28.2% of the total length of the year. The average coefficient of performance of the unit was 3.43 in Almaty and 4.63 in Kostanay. Although the installation with radiation cooling is operational, in the proposed scenario its practical application is not advisable.
Investigation of the processes of adsorbent regeneration by compression heat in an adsorption dryer of compressed air
Authors: Kozlov V. V. , Piskun E. S. , Ilicheva O. S.
Published: October 2020

The results of numerical modeling of the processes of drying and regeneration of the adsorbent by heat of compression are presented on the example of the scheme of adsorption drying with the separation of the air flow on the stage of the cooling of the adsorbent. The dynamics of temperature and humidity parameters within the technological columns at all three stages of the adsorption and regeneration cycle was evaluated. It is shown that the considered scheme of adsorption drying allows to provide rather stable average dew point of the dried compressed air without losses on the adsorbent purging.
Numerical modeling of ventilation and air conditions systems of large sport and culture centres
Authors: Kolosov Michail A. , Egorov Kirill S. , Novitskiy Bronislav B. , Malastowski Nikolay S. , Stepanova Larisa V.
Published: October 2020

One of the most promising applications of highly effective computer technology (supercomputers) is numerical simulation of complex physical and thermophysical proccesses occuring in vast areas of concert halls and sport arenas while heating, ventilating and air conditioning. According to Russian technical standarts for building construction, numerical modeling of these systems should be carried out on the stage of their design. The variety of problems and demands, lack of understanding of the physical process involved and the necessity to make genuine decisions are encountered while conducting such a work. The experience in modeling of ventilation and air conditioning systems of Bolshoi Krenlevskyi Palace concert halls and the Moscow Conservatory named after P.I. Chaikovskyi, Zaryadie Park Philarmony concert hall and a covered ice rink arena is described.
EIS study of the corrosion behavior of an organic coating applied on Algerian oil tanker
Authors: Hammouda Nadia , Belmokre Kamel
Published: October 2020

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in chloride environment (3% NaCl) by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness. Microscopic analyses have shown that oxidation dominates the corroded surfaces.
Autoimmune encephalitis and gastrointestinal dysmotility: achalasia, gastroparesis, and slow transit constipation
Authors: Frieling Thomas , Kreysel Christian , Blank Michael , Müller Dorothee , Melchior Ilka , Euler Philipp , Kuhlbusch-Zicklam Rita , Haarmeier Thomas , Schemann Michael
Published: October 2020

Background Neurological autoimmune disorders (NAD) are caused by autoimmune inflammation triggered by specific antibody subtypes. NAD may disturb the gut-brain axis at several levels including brain, spinal cord, peripheral, or enteric nervous system.

Case report We present a case with antinuclear neuronal Hu (ANNA-1)- and antiglial nuclear (SOX-1) autoimmune antibody-positive limbic encephalitis and significant gastrointestinal dysmotility consisting of achalasia type II, gastroparesis, altered small intestinal interdigestive motility, and severe slow transit constipation. The autoantibodies of the patient’s serum labeled enteric neurons and interstitial cells of Cajal but no other cells in the gut wall. Achalasia was treated successfully by pneumatic cardia dilation and gastrointestinal dysmotility successfully with prucalopride.

Conclusion NAD may disturb gastrointestinal motility by altering various levels of the gut-brain axis.
Schlaganfall und COVID-19
Authors: Diener Hans-Christoph , Berlit Peter
Published: October 2020

Im Rahmen der COVID-19-Infektion kommt es bei 0,5% bis 2 % der betroffenen Patienten zu einem Schlaganfall. Die Schlaganfälle sind meist schwer mit ungünstiger Prognose. Bei den meisten Patienten handelt es sich um einen Verschluss der großen hirnversorgenden Arterien bedingt durch die COVID-19 induzierte Gerinnungsstörung. Im Rahmen der COVID-19-Infektion ist es vorübergehend zu einem dramatischen Rückgang von Schlaganfallpatienten gekommen, die in Stroke Units behandelt werden. Die Situation hat sich in der Zwischenzeit wieder normalisiert.
Differentiation Between Ischemic and Hemorrhagic Strokes – A Pilot Study with Transtemporal Investigation of Brain Parenchyma Elasticity Using Ultrasound Shear Wave Elastography
Authors: Ertl Michael , Woeckel Margarethe , Maurer Christoph
Published: October 2020

Introduction Ultrasound shear wave elastography is well established in diagnostics of several parenchymatous organs and is recommended by respective guidelines. So far, research about applications in relevant neurological conditions is missing, especially in adults. Here we aimed to examine the method for the differentiation of ischemic (IS) and hemorrhagic strokes (HS) and cerebral mass effects.

Materials & Methods 50 patients with a confirmed diagnosis of HS or IS were enrolled in this prospective study. 2D shear wave elastography was performed on the ipsilateral and the contralateral side with a modified acoustic radiation force impulse (ARFI) technique (ElastPQ mode, Philips). Lesion volumetry was conducted based on computed tomography data for correlation with elastography results.

Results Elastography measurements (EM) revealed a highly significant difference between IS and HS with mean values of 1.94 and 5.50 kPa, respectively (p < 0.00 001). Mean values of brain tissue on the non-affected side were almost identical (IS 3.38 (SD = 0.63); HS 3.35 (SD = 0.66); p = 0.91). With a sensitivity of 0.98 and a specificity of 0.99, a cut-off value of 3.52 kPa for discrimination could be calculated. There was a significant correlation of mass effect represented by midline shift and EM values on the contralateral side (Pearson correlation coefficient = 0.68, p < 0.0003).

Conclusion Ultrasound brain parenchyma elastography seems to be a reliable sonographic method for discriminating between large IS and HS and for detecting and tracking conditions of intracerebral mass effects.
Fibrous Dysplasia, Paget's Disease of Bone, and Other Uncommon Sclerotic Bone Lesions of the Craniofacial Bones
Authors: Van de Voorde Nick , Mortier Geert R. , Vanhoenacker Filip M.
Published: October 2020

Imaging studies of the brain, head and neck, sinuses, and dental computed tomography are among the most frequently performed procedures in radiologic departments. Systematic evaluation in the bone window may reveal common and uncommon sclerotic osseous abnormalities of the craniofacial skeleton.

Most of these findings are incidental and unrelated to the initial clinical indications. Sporadically symptoms may arise due to lesional mass effect with compression on adjacent structures and neuroforaminal encroachment, resulting in proptosis, vision, or hearing loss. Other symptoms include craniofacial deformity, mandibular occlusion deformity, and local pain.

This article reviews the most common disorders characterized by an increased bone density involving the craniofacial bones including fibrous dysplasia, Paget's disease of bone, meningioma with associated hyperostosis, and osteoma. Finally, typical examples of rarer sclerosing bone dysplasias are discussed as well.

Emphasis is placed on imaging features and the differential diagnosis.
Facial and Dental Trauma
Authors: De Foer Bert , Bernaerts Anja , Dhont Kathleen , Casselman Jan W.
Published: October 2020

Dental and facial trauma are very common in a daily routine radiology practice. Knowledge of the functional anatomy of the mandibulofacial and maxillofacial regions forms the cornerstone of a thorough full radiologic evaluation of the patient with a dental and/or facial trauma. Cone beam computed tomography and multidetector computed tomography are currently considered the imaging modalities of choice. There are several patterns and classification systems for the various subtypes of mandibulofacial and maxillofacial fractures. They are discussed separately in this article with special attention to the types of dental trauma and orbital trauma.
Complete aggregation of the Lohe tensor model with the same free flow
Authors: Ha Seung-Yeal , Park Hansol
Published: October 2020

The Lohe tensor model is a first-order tensor-valued continuous-time dynamical system for the aggregation of tensors with the same rank and size. It reduces to the well-known aggregation models such as the Kuramoto model, the Lohe sphere model, and the Lohe matrix model as special cases for low-rank tensors. We present conditions for the solution splitting property, asymptotic convergence toward a set of equilibria, and analyze two possible asymptotic states (completely aggregate state and bi-polar state), which can emerge from a set of initial data. Moreover, we provide a sufficient framework leading to the aforementioned two asymptotic states in terms of initial data and system parameters.
Control of cavity flow with acoustic radiation by an intermittently driven plasma actuator
Authors: Yokoyama Hiroshi , Otsuka Keisuke , Otake Katsuya , Nishikawara Masahito , Yanada Hideki
Published: October 2020

In a cavity flow with acoustic radiation, self-sustained oscillations are controlled by a continuously or intermittently driven plasma actuator with elongated electrodes in the streamwise direction, which induces spanwise non-uniformity of the incoming boundary layer. To evaluate the control effects, wind tunnel experiments and compressible flow simulations were conducted. As indicated by sound pressure measurements at the fundamental frequency, the sound reduction level afforded by the intermittent control may be higher than that provided by the continuous control, although both have the same power consumption. In particular, the sound reduction was highest at a certain intermittent frequency (i.e., effective frequency) under a constant driving voltage and duty ratio. To clarify the mechanism for the influence of the intermittent frequency on the control effects, the time variation of the incoming boundary layer and cavity flow during the intermittent period was investigated. The oscillations remained weak under the control of the effective intermittent frequency, while the attenuation and amplification of the oscillations were repeated in the actuator-on and actuator-off durations, respectively, under the control of intermittent frequencies lower than the effective frequency. The amplification rate of the oscillations was found to be correlated with the quality factor of the radiated sound without control. The relationship between the effective frequency and characteristic time for this amplification is also discussed in this paper.
MDBenchmark: A toolkit to optimize the performance of molecular dynamics simulations
Authors: Gecht Michael , Siggel Marc , Linke Max , Hummer Gerhard , Köfinger Jürgen
Published: October 2020

Despite the impending flattening of Moore’s law, the system size, complexity, and length of molecular dynamics (MD) simulations keep on increasing, thanks to effective code parallelization and optimization combined with algorithmic developments. Going forward, exascale computing poses new challenges to the efficient execution and management of MD simulations. The diversity and rapid developments of hardware architectures, software environments, and MD engines make it necessary that users can easily run benchmarks to optimally set up simulations, both with respect to time-to-solution and overall efficiency. To this end, we have developed the software MDBenchmark to streamline the setup, submission, and analysis of simulation benchmarks and scaling studies. The software design is open and as such not restricted to any specific MD engine or job queuing system. To illustrate the necessity and benefits of running benchmarks and the capabilities of MDBenchmark, we measure the performance of a diverse set of 23 MD simulation systems using GROMACS 2018. We compare the scaling of simulations with the number of nodes for central processing unit (CPU)-only and mixed CPU–graphics processing unit (GPU) nodes and study the performance that can be achieved when running multiple simulations on a single node. In all these cases, we optimize the numbers of message passing interface (MPI) ranks and open multi-processing (OpenMP) threads, which is crucial to maximizing performance. Our results demonstrate the importance of benchmarking for finding the optimal system and hardware specific simulation parameters. Running MD simulations with optimized settings leads to a significant performance increase that reduces the monetary, energetic, and environmental costs of MD simulations.
The robust residual-based adaptive estimation Kalman filter method for strap-down inertial and geomagnetic tightly integrated navigation system
Authors: Zhai Hong-Qi , Wang Li-Hui
Published: October 2020

When noise statistical characteristics of the system are unknown and there are outliers in the measurement information, the filtering accuracy of the strap-down inertial navigation system/geomagnetic navigation system (SINS/GNS) tightly integrated navigation system would decrease, and the filtering may diverge in severe cases. To solve this problem, a robust residual-based adaptive estimation Kalman filter (RRAEKF) method is proposed. In the RRAEKF method, the covariance matching technique is employed to detect whether the system is abnormal or not. When the system is judged to be abnormal, a weighted factor is constructed to identify and weight the wild value in the measurement information, eliminating the influence of the outliers on the filtering accuracy. To further improve the filtering accuracy of the integrated navigation system, a contraction factor is introduced to adaptively adjust the gain matrix of the filter algorithm, obtaining the optimal estimate of the state vector and covariance matrix. Simulation results demonstrate that compared with the standard extended Kalman filter method and residual-based adaptive estimation method, the space position errors of the SINS/GNS tightly integrated navigation system based on the proposed method are improved by 63.37% and 56.93%, respectively, in the case of time-varying noise and the presence of outliers.
Cherry-picking resolvents: A general strategy for convergent coupled-cluster damped response calculations of core-level spectra
Authors: Nanda Kaushik D. , Krylov Anna I.
Published: October 2020

Damped linear response calculations within the equation-of-motion coupled-cluster singles and doubles (EOM-CCSD) framework usually diverge in the x-ray regime. This divergent behavior stems from the valence ionization continuum in which the x-ray response states are embedded. Here, we introduce a general strategy for removing the continuum from the response manifold while preserving important spectral properties of the model Hamiltonian. The strategy is based on decoupling the core and valence Fock spaces using the core–valence separation (CVS) scheme combined with separate (approximate) treatment of the core and valence resolvents. We illustrate this approach with the calculations of resonant inelastic x-ray scattering (RIXS) spectra of benzene and para-nitroaniline using EOM-CCSD wave functions and several choices of resolvents, which differ in their treatment of the valence manifold. The method shows robust convergence and extends the previously introduced CVS-EOM-CCSD RIXS scheme to systems for which valence contributions to the total cross section are important, such as the push–pull chromophores with charge-transfer states.
Network analysis reveals how lipids and other cofactors influence membrane protein allostery
Authors: Westerlund Annie M. , Fleetwood Oliver , Pérez-Conesa Sergio , Delemotte Lucie
Published: October 2020

Many membrane proteins are modulated by external stimuli, such as small molecule binding or change in pH, transmembrane voltage, or temperature. This modulation typically occurs at sites that are structurally distant from the functional site. Revealing the communication, known as allostery, between these two sites is key to understanding the mechanistic details of these proteins. Residue interaction networks of isolated proteins are commonly used to this end. Membrane proteins, however, are embedded in a lipid bilayer, which may contribute to allosteric communication. The fast diffusion of lipids hinders direct use of standard residue interaction networks. Here, we present an extension that includes cofactors such as lipids and small molecules in the network. The novel framework is applied to three membrane proteins: a voltage-gated ion channel (KCNQ1), a G-protein coupled receptor (GPCR—β2 adrenergic receptor), and a pH-gated ion channel (KcsA). Through systematic analysis of the obtained networks and their components, we demonstrate the importance of lipids for membrane protein allostery. Finally, we reveal how small molecules may stabilize different protein states by allosterically coupling and decoupling the protein from the membrane.
Dark field proton radiography
Authors: Freeman M. S. , Allison J. C. , Aulwes E. F. , Broder B. A. , Davis M. G. , Espy M. , Magnelind P. E. , Mariam F. G. , Martinez L. I. , Medina J. J. , Meijer W. Z. , Merrill F. E. , Morris C. , Neukirch L. P. , Prestridge K. P. , Saunders A. , Schurman T. , Sidebottom R. B. , Tainter A. M. , Tang Z. , Trouw F. R. , Tupa D. , Tybo J. L. , Wilde C. H.
Published: October 2020

A pre- and post-collimation scheme has been applied to high energy proton radiography to establish a dark field condition, which defaults to a state of no transmission until a scatterer is placed at the object plane. This technique, dark field proton radiography, provides two additional capabilities to a standard proton radiography setup. First, protons with a high degree of angular dispersion are removed from the beam, reducing the effects of chromatic aberrations and decreasing noise. Second, protons below the same threshold are removed from the beam downstream of the objects, effectively making the transmission highly sensitive to small amounts of scatter at the object plane. Initial results indicate that the system is highly sensitive to the presence of thinner materials and improves sensitivity to subtle areal density variations in thick objects.
Fluid transport through heterogeneous pore matrices: Multiscale simulation approaches
Authors: Phan Anh , Fan Dian , Striolo Alberto
Published: October 2020

Fluids confined in nanopores exhibit several unique structural and dynamical characteristics that affect a number of applications in industry as well as natural phenomena. Understanding and predicting the complex fluid behavior under nano-confinement is therefore of key importance, and both experimental and computational approaches have been employed toward this goal. It is now feasible to employ both simulations and theoretical methods, the results of which can be validated by cutting-edge experimental quantification. Nevertheless, predicting fluid transport through heterogeneous pore networks at a scale large enough to be relevant for practical applications remains elusive because one should account for a variety of fluid–rock interactions, a wide range of confined fluid states, as well as pore-edge effects and the existence of preferential pathways, which, together with many other phenomena, affect the results. The aim of this Review is to overview the significance of molecular phenomena on fluid transport in nanoporous media, the capability and shortcomings of both molecular and continuum fluid modeling approaches, and recent progress in multiscale modeling of fluid transport. In our interpretation, a multiscale approach couples a molecular picture for fluid interactions with solid surfaces at the single nanopore level with hierarchical transport analysis through realistic heterogeneous pore networks to balance physical accuracy with computational expense. When possible, comparison against experiments is provided as a guiding roadmap for selecting the appropriate computational methods. The appropriateness of an approach is certainly related to the final application of interest, as different sectors will require different levels of precision in the predictions.
Origin of irreversible to reversible transition in acetone detection for Y-doped BiFeO3 perovskite
Authors: Neogi S. , Ghosh R.
Published: October 2020

To eliminate the demerits of irreversibility associated with a gas-sensing material, it is always indispensable to know the exact origin of the same. In this view, the present study associates a perovskite to investigate the origin of irreversible sensing by a non-conventional bismuth ferrite (BiFeO3) nanomaterial prepared by a simple solgel technique. Yttrium (Y) doping in BiFeO3 significantly enhances the response performance and eliminates the irreversible nature, showing a reversible-type sensing behavior for selective detection of acetone (cross selectivity, Rcross = RAcetone/Rxylene: 20) along with the virtue of very low sensing ability (1 ppm), long-term stability with a negligible deviation in response value (R = 3.5 ± 0.25) toward 5 ppm acetone tested repeatedly for 300 days, and excellent repeatable over nine loops character desirable for practical application of the perovskite material. A remarkably highest response (R = ΔG/Ga) of 52 was achieved toward acetone utilizing Y-doped BiFeO3 perovskite. A possibility of the formation of closed pores and incomplete desorption of the reducing species (volatile organic compounds) from the active sites of the sensor has been considered the prime origin of unfinished recovery. Finally, irreversible to reversible transition in sensing has correlated with the structural and morphological change resulting from the substitution of the Bi3+ ion by the Y3+ ion, particularly at the A-site of the perovskite BiFeO3 due to Y-doping.
Development of electrochemical high-speed atomic force microscopy for visualizing dynamic processes of battery electrode materials
Authors: Liu Zhengliang , Bi Zhuanfang , Shang Yang , Liang Yaowen , Yang Peifa , Li Xiao , Zhang Chuandi , Shang Guangyi
Published: October 2020

Development of lithium ion batteries with ultrafast charging rate as well as high energy/power densities and long cycle-life is one of the imperative works in the field of batteries. To achieve this goal, it requires not only to develop new electrode materials but also to develop nano-characterization techniques that are capable of investigating the dynamic evolution of the surface/interface morphology and property of fast charging electrode materials during battery operation. Although electrochemical atomic force microscopy (EC-AFM) holds high spatial resolution, its imaging speed is too slow to visualize dynamics occurring on the timescale of minutes. In this article, we present an electrochemical high-speed AFM (EC-HS-AFM), developed by addressing key technologies involving optical detection of small cantilever deflection, dual scanner capable of high-speed and wide-range imaging, and electrochemical cell with three electrodes. EC-HS-AFM imaging from 1 fpm to ∼1 fps with a maximum scan range of 40 × 40 µm2 has been stably and reliably realized. Dynamic morphological changes in the LiMn2O4 nanoparticles during cyclic voltammetry measurements in the 0.5 mol/l Li2SO4 solution were successfully visualized. This technique will provide the possibility of tracking dynamic processes of fast charging battery materials and other surface/interface processes such as the formation of the solid electrolyte interphase layer.
Transferability of self-energy correction in tight-binding basis constructed from first principles
Authors: Hossain Manoar , Bhattacharjee Joydeep
Published: October 2020

We demonstrate in this work the transferability of self-energy (SE) correction (SEC) of Kohn–Sham (KS) single particle states from smaller to larger systems, when mapped through localized orbitals constructed from the KS states. The approach results in a SE corrected TB framework within which the mapping of SEC of TB parameters is found to be transferable from smaller to larger systems of similar morphology, leading to a computationally inexpensive approach for the estimation of SEC in large systems with reasonably high accuracy. The scheme has been demonstrated in insulating, semiconducting, and magnetic nanoribbons of graphene and hexagonal boron nitride, where the SEC tends to strengthen the individual π bonds, leading to transfer of charges from the edge to bulk. Additionally, in magnetic bipartite systems, the SEC tends to enhance inter-sublattice spin separation. The proposed scheme thus promises to enable the estimation of SEC of bandgaps of large systems without the need to explicitly calculate the SEC of KS single particle levels, which can be computationally prohibitively expensive.
Heterologous microProtein expression identifies LITTLE NINJA, a dominant regulator of jasmonic acid signaling
Authors: Hong Shin-Young , Sun Bin , Straub Daniel , Blaakmeer Anko , Mineri Lorenzo , Koch Jonas , Brinch-Pedersen Henrik , Holme Inger B. , Burow Meike , Lyngs Jørgensen Hans Jørgen , Albà M. Mar , Wenkel Stephan
Published: October 2020

Significance

In plants, hormone signaling is, to some extent, controlled by transcriptional repressors that are degraded in a hormone-dependent manner. These repressor complexes consist of multiple proteins that assemble. MicroProteins are small single-domain proteins that are sequence-related to larger, multidomain proteins and act by disrupting protein complex formation. By forming protein complexes, or by sequestering signaling proteins, microProteins can act as effective modulators of protein activity. Our studies have discovered LITTLE NINJA, a NINJA-related microProtein that modulates JA signaling by attenuating the repression of JA-signaling. Transgenic plants ectopically expressing LITTLE NINJA are shorter and bushier than wild-type plants. Modulating LITTLE NINJA activity may provide strategies for future crop improvement and contribute to finding sustainable solutions for future agricultural production.
Design rules for liquid crystalline electrolytes for enabling dendrite-free lithium metal batteries
Authors: Ahmad Zeeshan , Hong Zijian , Viswanathan Venkatasubramanian
Published: October 2020

Significance

Lithium metal anodes offer a promising approach to improve the energy density of batteries to enable electrification of transportation. Dendrite suppression plagues the safety and cycle life of lithium metal anodes. In this work, we perform a comprehensive analysis of the use of liquid crystalline electrolytes in lithium metal anodes. We report theoretical demonstration of spontaneous stabilization of metal-electrode position using a liquid crystalline electrolyte due to the energy that arises when the molecules of the liquid crystal reorient. Building on this, we develop a comprehensive set of molecular-level design rules that will pave the way toward the realization of this new class of electrolytes for practical lithium metal batteries.
Human sanctuaries can be created everywhere: pilgrimage, tourism, and conservation in Vrindavan, India.
Authors: Nash Joshua
Published: October 2020

This chapter focuses on how deeper and more philosophical experiences with sacred places, such as Vrindavan, India, can lead to the creation of human sanctuaries. Although present-day Vrindavan, which in popular mythological image is considered a celestial forest and divine playground of Krishna, is a city full of environmental problems, it still is the focus of spiritual teachings that build on the union of religion and nature conservation. In an almost biographical style, the author expounds on the Vaishnava teachings and their relevance for conserving the natural environment as he learned them from his study with local Vrindavan ecologist Shri Sevak Sharan, who calls for practical action and contemplative practice (sadhana, chintan) using what he calls the Vrindavan Ecological Concept (VEC). It is argued that this concept is powerful enough to inspire changes in thought processes and behavioural action that can create human sanctuaries everywhere in the world.
Interreligious dialogue: trees, stones, water, and interfaith ritual experiences in Lebanon.
Authors: Farra-Haddad Nour
Published: October 2020

The purpose of this chapter is to further explore interfaith pilgrimages in Lebanon through an examination of how elements in the natural landscape, such as trees, water, and stones are utilized by pilgrims. Many religious traditions around the world through human history have utilized these natural elements in religious rituals and religious community-building exercises. The chapter furthermore demonstrates that through interfaith devotions using these natural elements, an inter-sectarian conviviality is experienced by pilgrims that leads to a natural dialogue between them, leading in turn to the development of a culture of peace. This natural dialogue of life is especially vital for promoting a sustainable peace in the region.
Calibration of outer diameter standards (EURAMET.L-K4 2005.1)
Authors: Koops R , Bergmans R , Kotte G
Published: October 2020

At its meeting in October 2013, the EURAMET TC-L, decided upon a follow up comparison of the EUROMET.L-K4.2005 key comparison on diameter standards. This as a response to the executive report of the EUROMET.L-K4.2005 which contains several corrective actions to be performed for the following participants: INRIM, MIRS, NPL, SMD and VSL.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Advances in ultrafast gas-phase x-ray scattering
Authors: Stankus Brian , Yong Haiwang , Ruddock Jennifer , Ma Lingyu , Carrascosa Andres Moreno , Goff Nathan , Boutet Sébastien , Xu Xuan , Zotev Nikola , Kirrander Adam , Minitti Michael P , Weber Peter M
Published: October 2020

Recent developments of x-ray free electron lasers and pulsed electron sources have enabled ultrafast scattering to become an increasingly powerful tool for exploring molecular dynamics. This article describes our recent experimental and methodological advances in ultrafast gas-phase x-ray scattering experiments at the LCLS. A re-designed short-pathlength windowless diffractometer is coupled with careful optimization of sample density and independent normalization of x-ray intensity fluctuations to provide gas-phase scattering patterns with exceptionally high signal-to-noise ratios. These advances, coupled with careful geometry optimization and data treatment, provide both ground- and excited-state signals in excellent agreement with high level ab initio total scattering patterns.
Electro-thermal and optical characterization of an uncooled suspended bolometer based on an epitaxial La0.7Sr0.3MnO3 film grown on CaTiO3/Si
Authors: Nascimento V M , Méchin L , Liu S , Aryan A , Adamo C , Schlom D G , Guillet B
Published: October 2020

The electro-thermal and optical properties of a bolometer based on an La0.7Sr0.3MnO3( LSMO) thin film with a detection area of 100 × 100 µm2 are presented. The LSMO thin film was epitaxially grown on CaTiO3/Si and patterned using a two-step etching process of ion-beam etching in argon and of reactive-ion etching in SF6, in order to etch LSMO/CaTiO3 and Si, respectively. The voltage-current (V–I) characteristics of the bolometer were measured in vacuum from 240 K to 415 K. From the V–I characteristics and a thermal model of the bolometer, the electrical responsivity was determined and compared to the optical responsivity measured with a laser diode at 635 nm. The noise equivalent power (NEP) as a function of frequency was measured by dividing the spectral noise power density by the optical responsivity. At 300 K and a bias current of 80 µA, the NEP was 2.3 × 10−11 W · Hz−1/2 in the 20–200 Hz modulation frequency range and the response time was 1.3 ms. The obtained NEP value without any absorbing layer or antennas, combined with the low value of the response time, are a very promising step towards the use of such LSMO-based bolometers for IR or THz detection.
Apparent temperature in temperature-sensitive paint measurement and its effect on surface heat flux determination for hypersonic flows
Authors: Liu Xu , Shao Hongyi , Zhou Wenwu , Liu Yingzheng , Peng Di
Published: October 2020

Non-zero temperature gradients in temperature-sensitive paint (TSP) cause the apparent temperature (the temperature measured by the TSP) to correspond to the temperature somewhere inside the TSP, which does not equal the top surface temperature. Treating the apparent temperature as the average temperature across the TSP layer is not always accurate, especially when there is a large temperature gradient in the TSP. In this paper, the apparent temperature is theoretically derived by integrating the luminescent intensity across the TSP layer and numerically determined using a Monte Carlo ray-tracing method. The results of a simulation show that the difference between the apparent and average temperatures increases with the temperature gradient in the TSP layer, which leads to a non-negligible error when determining the surface heat flux based on the average temperature. A modified Levenberg–Marquardt algorithm is used to accurately recover the surface heat flux based on the apparent temperature for typical optical conditions in the measurement system. The results are compared with those obtained using the average temperature of the TSP. The effects of heat flux, TSP thickness and base material on the errors in the determination of the heat flux are investigated in detail.
Mesoscale strain and damage sensing in nanocomposite bonded energetic materials under low velocity impact with frictional heating via peridynamics
Authors: Talamadupula Krishna Kiran , Povolny Stefan J , Prakash Naveen , Seidel Gary D
Published: October 2020

The formation of hotspots within polymer bonded explosives can lead to the thermal decomposition and initiation of energetic materials. A frictional heating model is applied at the mesoscale in this study to assess the potential for the formation of hotspots under low velocity impact loadings. The frictional heating mechanism predominantly depends on the formation and growth of microstructural damage within the energetic material. Monitoring of the formation and growth of damage at the mesoscale is considered through the inclusion of piezoresistive carbon nanotube network within the energetic binder providing embedded strain and damage sensing. A coupled multiphysics thermo-electro-mechanical peridynamics framework is developed to perform computational simulations on an energetic material microstructure subject to low velocity impact loads. The coupled framework allows for the assessment of traveling compressive waves caused by impact with piezoresistive sensing, growth of damage with damage sensing and the possible formation of hotspots. The sensing mechanism has been shown to capture the presence of the compressive mechanical wave at different locations within the microstructure before large damage growth. It is observed that the development of hotspots is highly dependent on the impact energy. Higher impact energy leads to larger amounts of microstructural damage providing more damaged surfaces for friction to take place. The higher impact energy also yields larger relative velocities of sliding damage surfaces resulting in more frictional heating. With increase in impact energy, the model also predicts larger amounts of sensing and damage thereby supporting the use of carbon nanotubes to assess damage growth and subsequent formation of hotspots.
Numerical modeling of the magnetic response of interacting superparamagnetic particles to an ac field with arbitrary amplitude
Authors: Ambarov Alexander V , Zverev Vladimir S , Elfimova Ekaterina A
Published: October 2020

The dynamic magnetic response of immobilized superparamagnetic nanoparticles to an ac field with arbitrary amplitude is studied using numerical simulations. The nanoparticles are considered to be distributed randomly within an implicit solid matrix, but the easy axes of the particles are aligned parallel to the ac magnetic field. Modeling of dynamic response is based on the Fokker–Planck–Brown equation in which the interparticle dipole–dipole interactions are included within the framework of the modified mean-field theory. The effects of the magnetic crystallographic anisotropy barrier, the ac field amplitude, and the interparticle interactions on the dynamic magnetization, susceptibility, and relaxation time are analyzed. It is shown that an increase in the amplitude of the ac field significantly accelerates relaxation processes in the system under consideration whereas an increase in magnetic anisotropy of a particle and interparticle dipole–dipole interactions slows them down. The numerical results for dynamic susceptibility and relaxation time are compared against theories reliable in the weak ac field, and an excellent agreement is obtained.
Interaction of high-intensity focused ultrasound with polymers at the atomistic scale
Authors: Peng Kaiyuan , Shahab Shima , Mirzaeifar Reza
Published: October 2020

Experiments show that high-intensity focused ultrasound (HIFU) is a promising stimulus with multiple superior and unique capabilities to induce localized heating and achieve temporal and spatial thermal effects in the polymers, noninvasively. When polymers are subjected to HIFU, they heat up differently compared to the case they are subjected to heat sources directly; however, the origins of this difference are still entirely unknown. We hypothesize that the difference in the macroscale response of polymers subjected to HIFU strongly depends on the polymer chains, composition, and structure, i.e. being crystalline or amorphous. In this work, this hypothesis is investigated by molecular dynamics studies at the atomistic level and verified by experiments at the macroscopic scale. The results show that the viscoelasticity, measured by stress–strain phase lag, the reptation motion of the chains, and the vibration-induced local mobility quantified by the root mean square fluctuation contribute to the observed difference in the HIFU-induced thermal effects. This unravels the unknown mechanisms behind stimulating the polymers by HIFU, and paves the way in front of using this method in future applications.
Influence of chemical potential on shape evolution of 2D-MoS2 flakes produced by chemical vapor deposition
Authors: Raju Mula , Wan Meher , Sen Supriti , Jacob Chacko
Published: October 2020

High-quality, ultrathin 2D-MoS2 layers with large area were grown on SiO2/Si substrates by using atmospheric pressure chemical vapor deposition (APCVD) at elevated temperatures. The growth precursors (MoO3 and S) were placed separately inside the double-zone furnace to control the growth parameters individually for better flexibility in the growth process. In this study, it was found that the shape and edge structure of the evolved MoS2 flakes were significantly influenced by the chemical potential of the Mo and S precursor concentration. In keeping with the concentration gradient of the Mo precursor (MoO3) on the substrate surface, the shape of MoS2 flakes changed from hexagonal to truncated triangle and then to triangular shapes, owing to the Mo-rich to S-rich conditions. The surface roughness and thickness of the differently shaped MoS2 flakes were studied by using atomic force microscope (AFM). Additionally, Raman and photoluminescence (PL) techniques were employed to characterize the crystalline quality, number of grown layers and optical performance of the as-grown MoS2 layers. Auger electron spectroscopy (AES) analysis and scanning electron microscopy (SEM) confirmed that the equilibrium crystal shape of the MoS2 was hexagonal under Mo-rich conditions. However, the shape of the MoS2 crystal changed to a triangle under S-rich conditions. Furthermore, the influence of chemical potential on the edge structure of the monolayer MoS2 and its effect on the equilibrium shape of the crystal were studied.
Scalable and fast fabrication of holey multilayer graphene via microwave and its application in supercapacitors
Authors: Bai Yuge , Yin Yuting , Xuan Yingying , Han Xiaogang
Published: October 2020

By virtue of its high specific surface area and low tortuosity for ionic storage and transportation, holey graphene has come to be regarded as a promising material for energy storage devices, such as lithium ion batteries, and supercapacitors. For practical applications, a scalable and green preparation method for holey graphene is required. This work proposes a facile preparation method for holey graphene by simply microwaving pristine graphene in air. Compared with previous scalable methods, this method exhibits much greater efficiency, reducing the preparation time from hours to minutes. The mechanism underlying the microwave irradiation-induced formation of nanosized holes involves the interaction between microwaves, electrons, oxygen in air, and carbon atoms in the defect areas of the graphene. The size, density, and distribution of holes can be controlled by tuning the microwave irradiation time and oxygen concentration. Used as a hybrid conductive agent, the as-prepared holey multilayer graphene increases capacitance retention to 96.25% at high current density (8 A g−1), and 96.48% in long cycles (1 A g−1 and 10 000 cycles).